Cisco Systems OL-4266-08 User Manual

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42
Configuring PFC QoS
This chapter describes how to configure quality of service (QoS) as implemented on the Policy Feature Card (PFC) and Distributed Forwarding Cards (DFCs) on the Cisco 7600 series routers.
Cisco 7600 Series Router Cisco IOS Command Reference at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/software/122sx/cmdref/index.htm
For information about QoS and MPLS, see Chapter 43, “Configuring PFC3BXL or PFC3B Mode
MPLS QoS.”
QoS on the Cisco 7600 series routers (PFC QoS) uses some Cisco IOS modular QoS CLI (MQC).
Because PFC QoS is implemented in hardware, it supports only a subset of the MQC syntax.
The PFC3 does not support Network-Based Application Recognition (NBAR).
With a Supervisor Engine 2, PFC2, and MSFC2, you can configure NBAR on Layer 3 interfaces
instead of PFC QoS:
The PFC2 provides hardware support for input ACLs on ports where you configure NBAR.
When PFC QoS is enabled, the traffic through ports where you configure NBAR passes through the ingress and egress queues and drop thresholds.
When PFC QoS is enabled, the MSFC2 sets egress CoS equal to egress IP precedence in NBAR traffic.
After passing through an ingress queue, all traffic is processed in software on the MSFC2 on interfaces where you configure NBAR.
To configure NBAR, refer to this publication:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t8/dtnba rad.htm
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This chapter contains these sections:
Understanding How PFC QoS Works, page 42-2
PFC QoS Default Configuration, page 42-28
PFC QoS Configuration Guidelines and Restrictions, page 42-49
Configuring PFC QoS, page 42-55
Common QoS Scenarios, page 42-112
PFC QoS Glossary, page 42-122
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Understanding How PFC QoS Works

Understanding How PFC QoS Works
The term “PFC QoS” refers to QoS on the Cisco 7600 series router. PFC QoS is implemented on various router components in addition to the PFC and any DFCs. These sections describe how PFC QoS works:
Port Types Supported by PFC QoS, page 42-2
Overview, page 42-2
Component Overview, page 42-6
Understanding Classification and Marking, page 42-16
Understanding Port-Based Queue Types, page 42-22

Port Types Supported by PFC QoS

The PFC does not provide QoS for FlexWAN module ports. Refer to this publication for information about FlexWAN module QoS features:
http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/cfgnotes/flexport/combo/index.htm
In all releases, PFC QoS supports LAN ports. LAN ports are Ethernet ports on Ethernet switching modules, except for the 4-port Gigabit Ethernet WAN (GBIC) modules (OSM-4GE-WAN and OSM-2+4GE-WAN+). Some OSMs have four Ethernet LAN ports in addition to WAN ports.
With Release 12.2(17b)SXA and later releases, PFC QoS supports optical services module (OSM) ports. OSM ports are the WAN ports on OSMs. Refer to the following publication for information about additional OSM QoS features:
Chapter 42 Configuring PFC QoS

Overview

http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/cfgnotes/osm_inst/index.htm
Typically, networks operate on a best-effort delivery basis, which means that all traffic has equal priority and an equal chance of being delivered in a timely manner. When congestion occurs, all traffic has an equal chance of being dropped.
QoS makes network performance more predictable and bandwidth utilization more effective. QoS selects (classifies) network traffic, uses or assigns QoS labels to indicate priority, makes the packets comply with the configured resource usage limits (polices the traffic and marks the traffic), and provides
congestion avoidance where resource contention exists.
PFC QoS classification, policing, marking, and congestion avoidance is implemented in hardware on the PFC, DFCs, and in LAN switching module port Application Specific Integrated Circuits (ASICs).
Note Cisco 7600 series routers do not support all of the MQC features (for example, Committed Access Rate
(CAR)) for traffic that is Layer 3 switched or Layer 2 switched in hardware. Because queuing is implemented in the port ASICs, Cisco 7600 series routers do not support MQC-configured queuing.
Figure 42-1 shows an overview of QoS processing in a Cisco 7600 series router.
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Chapter 42 Configuring PFC QoS
Figure 42-1 PFC QoS Feature Processing Overview
MSFC
2
2
PFC
Understanding How PFC QoS Works
Switching
Module
1
1
Switching
Module
3
3
120559
The PFC QoS features are applied in this order:
1. Ingress port PFC QoS features:
Port trust state—In PFC QoS, trust means to accept as valid and use as the basis of the initial
internal DSCP value. Ports are untrusted by default, which sets the initial internal DSCP value
to zero. You can configure ports to trust received CoS, IP precedence, or DSCP.
Layer 2 CoS remarking—PFC QoS applies Layer 2 CoS remarking, which marks the incoming frame with the port CoS value, in these situations:
—If the traffic is not in an ISL, 802.1Q, or 802.1p frame.
—If a port is configured as untrusted.
On OSM ATM and POS ports, PFC QoS always sets ingress CoS equal to zero.
Congestion avoidance—If you configure an Ethernet LAN port to trust CoS or DSCP, QoS
classifies the traffic on the basis of its Layer 2 CoS value or its Layer 3 DSCP value and assigns it to an ingress queue to provide congestion avoidance. Layer 3 DSCP-based queue mapping is available only on WS-X6708-10GE ports.
2. PFC and DFC QoS features:
Internal DSCP—On the PFC and DFCs, QoS associates an internal DSCP value with all traffic
to classify it for processing through the system. There is an initial internal DSCP based on the traffic trust state and a final internal DSCP. The final internal DSCP can be the same as the initial value or an MQC policy map can set it to a different value.
MQC policy maps—MQC policy maps can do one or more of these operations:
—Change the trust state of the traffic (bases the internal DSCP value on a different QoS label)
—Set the initial internal DSCP value (only for traffic from untrusted ports)
—Mark the traffic
—Police the traffic
3. Egress Ethernet LAN port QoS features:
Layer 3 DSCP marking with the final internal DSCP (always with PFC2, optionally with PFC3)
Layer 2 CoS marking mapped from the final internal DSCP
Layer 2 CoS-based and Layer 3 DSCP-based congestion avoidance. (Layer 3 DSCP-based
queue mapping is available only on WS-X6708-10GE ports.)
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Understanding How PFC QoS Works
These figures provide more detail about the relationship between QoS and the router components:
Figure 42-2, Traffic Flow and PFC QoS Features with PFC3
Figure 42-3, Traffic Flow and PFC QoS Features with PFC2
Figure 42-4, PFC QoS Features and Component Overview
Figure 42-2 shows traffic flow and PFC QoS features with a PFC3.
Figure 42-2 Traffic Flow and PFC QoS Features with PFC3
Chapter 42 Configuring PFC QoS
FlexWAN traffic
enters switch
LAN traffic
enters switch
OSM traffic
enters switch
CoS = 0 for all ATM and POS traffic (not configurable)
FlexWAN
ingress port and
QoS features
LAN ingress
port and
QoS features
OSM ingress
port and
QoS freatures
Ingress
PFC3
QoS
Figure 42-2 shows how traffic flows through the PFC QoS features with PFC3:
Traffic can enter on any type of port and exit on any type of port.
DFCs implement PFC QoS locally on switching modules.
For FlexWAN module traffic:
Ingress FlexWAN QoS features can be applied to FlexWAN ingress traffic.
Ingress FlexWAN traffic can be Layer 3-switched by the PFC3 or routed in software by the MSFC.
Egress PFC QoS is not applied to FlexWAN ingress traffic.
Multilayer Switch
Feature Card
(MSFC)
PFC3
Layer 2 or 3
switching
Egress
PFC3
QoS
FlexWAN
egress port and
QoS features
CoS = IP precedence for all traffic (not configurable)
LAN egress
port and
QoS features
OSM egress
port and
QoS freatures
Transmit
FlexWAN traffic
Transmit
LAN traffic
Transmit
OSM traffic
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Egress FlexWAN QoS can be applied to FlexWAN egress traffic.
For LAN-port traffic:
Ingress LAN-port QoS features can be applied to LAN-port ingress traffic.
Ingress PFC QoS can be applied to LAN-port ingress traffic.
Ingress LAN-port traffic can be Layer-2 or Layer-3 switched by the PFC3 or routed in software by the MSFC.
Egress PFC QoS and egress LAN-port QoS can be applied to LAN-port egress traffic.
For OSM traffic:
Ingress OSM-port QoS features can be applied to OSM-port ingress traffic.
Ingress PFC3 QoS can be applied to OSM-port ingress traffic.
Ingress OSM-port traffic can be Layer-3 switched by the PFC3 or routed in software by the MSFC.
Egress PFC3 QoS and egress OSM-port QoS can be applied to OSM-port egress traffic.
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Figure 42-3 shows traffic flow and PFC QoS features with a PFC2.
Figure 42-3 Traffic Flow and PFC QoS Features with PFC2
Understanding How PFC QoS Works
FlexWAN traffic
enters switch
LAN traffic
enters switch
OSM traffic
enters switch
CoS = 0 for all ATM and POS traffic (not configurable)
FlexWAN
ingress port and
QoS features
LAN ingress
port and
QoS features
OSM ingress
port and
QoS freatures
Ingress
PFC2
QoS
Figure 42-3 shows how traffic flows through the PFC QoS features with PFC2:
Traffic can enter on any type of port and exit on any type of port.
DFCs implement PFC QoS locally on switching modules.
For FlexWAN module traffic:
Ingress FlexWAN QoS features can be applied to FlexWAN ingress traffic.
Ingress FlexWAN traffic can be Layer 3-switched by the PFC2 or routed in software by the MSFC2.
Egress FlexWAN QoS can be applied to FlexWAN egress traffic.
For LAN-port traffic:
Multilayer Switch
Feature Card 2
(MSFC2)
PFC2
Layer 2 or 3
switching
FlexWAN
egress port and
QoS features
CoS = IP precedence for all traffic (not configurable)
LAN egress
port and
QoS features
OSM egress
port and
QoS freatures
Transmit
FlexWAN traffic
Transmit
LAN traffic
Transmit
OSM traffic
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Ingress LAN-port QoS features can be applied to LAN-port ingress traffic.
Ingress LAN-port traffic can be Layer-2 or Layer-3 switched by the PFC2 or routed in software by the MSFC2.
Egress LAN-port QoS can be applied to LAN-port egress traffic.
For OSM traffic:
OSM-port QoS features can be applied to OSM-port ingress traffic.
Ingress PFC2 QoS can be applied to OSM-port ingress traffic.
OSM-port ingress traffic can be Layer-3 switched by the PFC2 or routed in software by the MSFC2.
Egress OSM-port QoS can be applied to OSM-port egress traffic.
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Understanding How PFC QoS Works
Figure 42-4 PFC QoS Features and Component Overview
Identify traffic based on match criteria:
Por t Trus t
- CoS
- IP Prec
- DSCP
- MPLS Exp
DSCP
map
- ACL (L2, IP)
- DSCP
- IP Prec
- MPLS Exp
- Class-map
Final internal
DSCP is
mapped to CoS
Chapter 42 Configuring PFC QoS
Scheduler operates
on WRR, DWRR,
SP
Incoming
To S
CoS
Ingress Port
Q1
Scheduler
Q2
Scheduling rules: WRR, PQ
Queueing based on CoS
C
l a s s
i
f
Policy Result
i c a
t
i o n
Action - policy map
Trust - DSCP, IP Prec
Mark - set internal
Police - rate limit; mark; drop
MPLS Exp
DSCP
Egress PortPFC/DFC
DSCP CoS
rewrite
CoS determies
queue selection
Q1
Q2
WRR DWRR
Q3
Q4
Scheduler queue
and threshold are
configurable
SP
Outgoing
CoS set on trunk port DSCP set for IP
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Component Overview

These sections provide more detail about the role of the following components in PFC QoS decisions and processes:
Ingress LAN Port PFC QoS Features, page 42-6
PFC and DFC QoS Features, page 42-8
PFC QoS Egress Port Features, page 42-12

Ingress LAN Port PFC QoS Features

These sections provide an overview of the ingress port QoS features:
Flowchart of Ingress LAN Port PFC QoS Features, page 42-7
Port Trust, page 42-8
Ingress Congestion Avoidance, page 42-8
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Flowchart of Ingress LAN Port PFC QoS Features
Figure 42-5 shows how traffic flows through the ingress LAN port PFC QoS features.
Figure 42-5 Ingress LAN Port PFC QoS Features
Frame
enters switch
ISL or
802.1Q?
Yes
Port set to
untrusted?
No
Ye s
Apply
port
CoS
IP
traffic with
recognizable
ToS byte?
Yes
Ignore port trust enabled?
Understanding How PFC QoS Works
No
Apply
port
CoS
No
No
Port set to
trust-ipprec?
No
Port set to
trust-dscp?
No
Port is set to
trust-cos
Ye s
No
IP
DSCP-based
Ye s Ye s Ye s
queue mapping
enabled?
traffic with
recognizable
ToS byte?
No
CoS-to-queue
Ye s
map
Mutate
CoS
No
Ingress
CoS
Mutation?
DSCP-to-queue
map
Ingress queues and
drop thresholds
154684
To
PFC
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Note Ingress CoS mutation is supported only on 802.1Q tunnel ports.
Release 12.2(18)SXF5 and later releases support the ignore port trust feature.
DSCP-based queue mapping is supported only on WS-X6708-10GE ports.
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Understanding How PFC QoS Works
Port Trust
Chapter 42 Configuring PFC QoS
In PFC QoS, trust means to accept as valid and use as the basis of the initial internal DSCP value. You can configure ports as untrusted or you can configure them to trust these QoS values:
Layer 2 CoS
A port configured to trust CoS is called a trust CoS port.
Traffic received through a trust CoS port or configured by a policy map to trust CoS is called trust CoS traffic.
Note Not all traffic carries a CoS value. Only ISL, 802.1Q, and 802.1P traffic carries a CoS value.
PFC QoS applies the port CoS value to any traffic that does not carry a CoS value. On untrusted ports, PFC QoS applies the port CoS value to all traffic, overwriting any received CoS value.
IP precedence
A port configured to trust IP precedence is called a trust IP precedence port.
Traffic received through a trust IP precedence port or configured by a policy map to trust IP precedence is called trust IP precedence traffic.
DSCP
A port configured to trust DSCP is called a trust DSCP port.
Traffic received through a trust DSCP port or configured by a policy map to trust DSCP is called trust DSCP traffic.
Traffic received through an untrusted port is called untrusted traffic.
Ingress Congestion Avoidance
PFC QoS implements congestion avoidance on trust CoS ports. On a trust CoS port, QoS classifies the traffic on the basis of its Layer 2 CoS value and assigns it to an ingress queue to provide congestion avoidance. In Release 12.2(18)SXF5 and later releases, you can configure WS-X6708-10GE trust DSCP
ports to use received DSCP values for congestion avoidance. See the “Ingress Classification and Marking at Trust CoS LAN Ports” section on page 42-17 for more information about ingress congestion
avoidance.

PFC and DFC QoS Features

These sections describe PFCs and DFCs as they relate to QoS:
Supported Policy Feature Cards, page 42-9
Supported Distributed Forwarding Cards, page 42-9
PFC and DFC QoS Feature List and Flowchart, page 42-9
Internal DSCP Values, page 42-11
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Chapter 42 Configuring PFC QoS
Supported Policy Feature Cards
The policy feature card (PFC) is a daughter card that resides on the supervisor engine. The PFC provides QoS in addition to other functionality. The following PFCs are supported on the Cisco 7600 series routers:
PFC2 on the Supervisor Engine 2
PFC3A on the Supervisor Engine 720
PFC3B on the Supervisor Engine 720 and Supervisor Engine 32
PFC3BXL on the Supervisor Engine 720
Supported Distributed Forwarding Cards
The PFC sends a copy of the QoS policies to the distributed forwarding card (DFC) to provide local support for the QoS policies, which enables the DFCs to support the same QoS features that the PFC supports.
The following DFCs are supported on the Cisco 7600 series routers:
WS-F6K-DFC, for use on dCEF256 and CEF256 modules with a Supervisor Engine 2.
WS-F6K-DFC3A, WS-F6K-DFC3B, WS-F6K-DFC3BXL, for use on dCEF256 and CEF256
modules with a Supervisor Engine 720.
Understanding How PFC QoS Works
WS-F6700-DFC3A, WS-F6700-DFC3B, WS-F6700-DFC3BXL, for use on CEF720 modules with
a Supervisor Engine 720.
PFC and DFC QoS Feature List and Flowchart
Table 42-1 lists the QoS features supported on the different versions of PFCs and DFCs.
Table 42-1 QoS Features Supported on PFCs and DFCs
Feature PFC2/DFC PFC3A/DFC3A PFC3B/DFC3B PFC3BXL/DFC3BXL
Support for DFCs Yes Yes Yes Yes
Flow granularity Full flow Source
Destination
Source Destination
Source Destination
QoS ACLs IP, IPX, MAC IP, MAC IP, MAC IP, MAC
DSCP transparency
Note Enabling DSCP transparency disables
No Optional Optional Optional
egress ToS rewrite.
Egress ToS rewrite Mandatory Optional Optional Optional
Policing:
Ingress aggregate policers Yes Yes Yes Yes
Egress aggregate policers No Yes Yes Yes
Number of aggregate policers 1022 1022 1022 1022
Microflow policers 64 rates 64 rates 64 rates 64 rates
Number of flows per Microflow policer 32,000 64,000 110,000 240,000
Unit of measure for policer statistics Packets Bytes Bytes Bytes
Basis of policer operation Layer 3 length Layer 2 length Layer 2 length Layer 2 length
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Figure 42-6 shows how traffic flows through the QoS features on the PFC and DFCs.
Figure 42-6 QoS Features on the PFC and DFCs
Ingress PFC QoS
For trust CoS traffic:
CoS
(Received or Port)
For trust DSCP traffic:
Received
DSCP
For trust IP precedence traffic:
Received IP Precedence
For untrusted traffic or for any traffic if ignore port trust is configured
When ignore port trust is not configured
When ignore port trust is configured, received DSCP (if any) is initial internal DSCP, otherwise port CoS is mapped to initial internal DSCP
Map
Map
Initial Internal DSCP=0
Initial
Internal
DSCP
Initial
Internal
DSCP
Initial
Internal
DSCP
Policy map
Policer Marker
(Optional)
Policy map
Policer Marker
(Optional)
Policy map
Policer Marker
(Optional)
Policy map
Policer Marker
(Optional)
Traffic Forwarding
MSFC routing
or
PFC Layer 3
switching
or
PFC Layer 2
switching
Policy map
Policer Marker
(Optional;
only
with PFC 3)
Chapter 42 Configuring PFC QoS
Egress PFC QoS
Egress
DSCP
Final
Internal
DSCP
Map
Mutation
Map
(only on PFC3)
Egress CoS
(LAN ports only)
Egress
DSCP
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Note The DSCP transparency feature makes writing the egress DSCP value into the Layer 3 ToS byte optional.
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Chapter 42 Configuring PFC QoS
Internal DSCP Values
During processing, PFC QoS represents the priority of all traffic (including non-IP traffic) with an internal DSCP value.
Initial Internal DSCP Value
On the PFC, before any marking or policing takes place, PFC QoS derives the initial internal DSCP value as follows:
Understanding How PFC QoS Works
For untrusted traffic, when ignore port trust is not enabled, PFC QoS sets the initial internal DSCP
value to zero for both tagged and untagged untrusted traffic.
For untrusted traffic, when ignore port trust is enabled, PFC QoS does the following:
For IP traffic, PFC QoS uses the received DSCP value as the initial internal DSCP value.
For traffic without a recognizable ToS byte, PFC QoS maps the port CoS value to the initial internal DSCP value.
For trust CoS traffic, when ignore port trust is enabled, PFC QoS does the following:
For IP traffic, PFC QoS uses the received DSCP value as the initial internal DSCP value.
Note For trust CoS traffic, when ignore port trust is enabled, PFC QoS does not use the
received CoS value in tagged IP traffic.
For tagged traffic without a recognizable ToS byte, PFC QoS maps the received CoS value to the initial internal DSCP value.
For untagged traffic without a recognizable ToS byte, PFC QoS maps the port CoS value to the initial internal DSCP value.
For trust IP precedence traffic, PFC QoS does the following:
For IP traffic, PFC QoS maps the received IP precedence value to the initial internal DSCP value.
For tagged traffic without a recognizable ToS byte, PFC QoS maps the received CoS value to the initial internal DSCP value.
For untagged traffic without a recognizable ToS byte, PFC QoS maps the port CoS value to the initial internal DSCP value.
For trust DSCP traffic, PFC QoS, PFC QoS does the following:
For IP traffic, PFC QoS uses the received DSCP value as the initial internal DSCP value.
For tagged traffic without a recognizable ToS byte, PFC QoS maps the received CoS value to the initial internal DSCP value.
For untagged traffic without a recognizable ToS byte, PFC QoS maps the port CoS value to the initial internal DSCP value.
For trust CoS traffic and trust IP precedence traffic, PFC QoS uses configurable maps to derive the initial internal 6-bit DSCP value from CoS or IP precedence, which are 3-bit values.
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Final Internal DSCP Value
Policy marking and policing on the PFC can change the initial internal DSCP value to a final internal DSCP value, which is then used for all subsequently applied QoS features.
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Understanding How PFC QoS Works
Port-Based PFC QoS and VLAN-Based PFC QoS
You can configure each ingress LAN port for either physical port-based PFC QoS (default) or VLAN-based PFC QoS and attach a policy map to the selected interface.
On ports configured for port-based PFC QoS, you can attach a policy map to the ingress LAN port as follows:
On a nontrunk ingress LAN port configured for port-based PFC QoS, all traffic received through the
port is subject to the policy map attached to the port.
On a trunking ingress LAN port configured for port-based PFC QoS, traffic in all VLANs received
through the port is subject to the policy map attached to the port.
On a nontrunk ingress LAN port configured for VLAN-based PFC QoS, traffic received through the port is subject to the policy map attached to the port’s VLAN.
On a trunking ingress LAN port configured for VLAN-based PFC QoS, traffic received through the port is subject to the policy map attached to the traffic’s VLAN.

PFC QoS Egress Port Features

Chapter 42 Configuring PFC QoS
These sections describe PFC QoS egress port features:
Flowchart of PFC QoS Egress LAN Port Features, page 42-13
Egress CoS Values, page 42-13
Egress DSCP Mutation with a PFC3, page 42-14
Egress ToS Byte, page 42-14
Egress PFC QoS Interfaces, page 42-14
Egress ACL Support for Remarked DSCP, page 42-14
Marking on Egress OSM Ports, page 42-15
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Flowchart of PFC QoS Egress LAN Port Features
Figure 42-7 shows how traffic flows through the QoS features on egress LAN ports.
Figure 42-7 Egress LAN Port Scheduling, Congestion Avoidance, and Marking
From
PFC or MSFC
Egress queues and
drop thresholds
IP traffic
from PFC?
No
Understanding How PFC QoS Works
PFC3
only
Ye s Ye s
DSCP
rewrite
enabled?
No
Write ToS
byte into
packet
Egress CoS Values
Note With Release 12.2(18)SXF5 and later releases, you can configure WS-X6708-10GE ports to use the final
Write CoS
ISL or
802.1Q?
No
Transmit
frame
Ye s
into
frame
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For all egress traffic, PFC QoS uses a configurable map to derive a CoS value from the final internal
DSCP value associated with the traffic. PFC QoS sends the derived CoS value to the egress LAN ports
for use in classification and congestion avoidance and to be written into ISL and 802.1Q frames.
internal DSCP value for egress LAN port classification and congestion avoidance (see the “Configuring
DSCP-Based Queue Mapping” section on page 42-98).
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Egress DSCP Mutation with a PFC3
With a PFC3, you can configure 15 egress DSCP mutation maps to mutate the internal DSCP value before it is written in the egress ToS byte. You can attach egress DSCP mutation maps to any interface that PFC QoS supports.
Note If you configure egress DSCP mutation, PFC QoS does not derive the egress CoS value from the
mutated DSCP value.
The PFC2 does not support egress DSCP mutation.
Egress ToS Byte
Except when DSCP transparency is enabled, PFC QoS creates a ToS byte for egress IP traffic from the final internal or mutated DSCP value and sends it to the egress port to be written into IP packets. For trust DSCP and untrusted IP traffic, the ToS byte includes the original two least-significant bits from the received ToS byte.
The internal or mutated DSCP value can mimic an IP precedence value (see the “IP Precedence and
DSCP Values” section on page 42-55).
Chapter 42 Configuring PFC QoS
Egress PFC QoS Interfaces
You can attach an output policy map to a Layer 3 interface (either a LAN port configured as a Layer 3 interface or a VLAN interface) to apply a policy map to egress traffic.
Note Output policies do not support microflow policing.
With a PFC3, you cannot apply microflow policing to ARP traffic.
You cannot set a trust state in an output policy.
Egress ACL Support for Remarked DSCP
Note Egress ACL support for remarked DSCP is also known as packet recirculation.
With a PFC3, Release 12.2(18)SXE and later releases support egress ACL support for remarked DSCP, which enables IP precedence-based or DSCP-based egress QoS filtering to use any IP precedence or DSCP policing or marking changes made by ingress PFC QoS.
Without egress ACL support for remarked DSCP, egress QoS filtering uses received IP precedence or DSCP values; it does not use any IP precedence or DSCP changes made by ingress PFC QoS as the result of policing or marking.
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The PFC3 provides egress PFC QoS only for Layer 3-switched and routed traffic on egress Layer 3 interfaces (either LAN ports configured as Layer 3 interfaces or VLAN interfaces).
You configure egress ACL support for remarked DSCP on ingress Layer 3 interfaces (either LAN ports configured as Layer 3 interfaces or VLAN interfaces).
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On interfaces where egress ACL support for remarked DSCP is configured, the PFC3 processes each QoS-filtered IP packet twice: once to apply ingress PFC QoS and once to apply egress PFC QoS.
Caution If the router is operating in PFC3A mode with egress ACL support for remarked DSCP configured, when
the PFC3 processes traffic to apply ingress PFC QoS, it applies ingress PFC QoS filtering and ingress PFC QoS, and incorrectly applies any egress QoS filtering and egress PFC QoS configured on the ingress interface, which results in unexpected behavior if QoS filtering is configured on an interface where egress ACL support for remarked DSCP is enabled. This problem does not occur in other PFC3 modes.
After packets have been processed by ingress PFC QoS and any policing or marking changes have been made, the packets are processed again on the ingress interface by any configured Layer 2 features (for example, VACLs) before being processed by egress PFC QoS.
On an interface where egress ACL support for remarked DSCP is configured, if a Layer 2 feature matches the ingress-QoS-modified IP precedence or DSCP value, the Layer 2 feature might redirect or drop the matched packets, which prevents them from being processed by egress QoS.
After packets have been processed by ingress PFC QoS and any policing or marking changes have been made, the packets are processed on the ingress interface by any configured Layer 3 features (for example, ingress Cisco IOS ACLs, policy based routing (PBR), etc.) before being processed by egress PFC QoS.
Understanding How PFC QoS Works
The Layer 3 features configured on an interface where egress ACL support for remarked DSCP is configured might redirect or drop the packets that have been processed by ingress PFC QoS, which would prevent them from being processed by egress PFC QoS.
Marking on Egress OSM Ports
Ingress PFC QoS sets DSCP values that can be used by the OSM egress QoS features (see Figure 42-8).
Figure 42-8 Egress OSM Port Marking
From PFC or
MSFC
IP traffic
from PFC?
No
OSM
QoS
Features
OSM switching module marking
PFC3
only
Ye s Ye s
DSCP
rewrite
enabled?
No
Write ToS
byte into
packet
113090
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OSM traffic
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Understanding Classification and Marking

The following sections describe where and how classification and marking occur on the Cisco 7600 series routers:
Classification and Marking at Trusted and Untrusted Ingress Ports, page 42-16
Classification and Marking at Ingress OSM Ports, page 42-17
Classification and Marking on the PFC Using Service Policies and Policy Maps, page 42-18
Classification and Marking on the MSFC, page 42-19

Classification and Marking at Trusted and Untrusted Ingress Ports

The trust state of an ingress port determines how the port marks, schedules, and classifies received Layer 2 frames, and whether or not congestion avoidance is implemented. These are the port trust states:
Untrusted (default)
Trust IP precedence
Trust DSCP
Trust CoS
Chapter 42 Configuring PFC QoS
In all releases, ingress LAN port classification, marking, and congestion avoidance can use Layer 2 CoS values and do not set Layer 3 IP precedence or DSCP values.
In Release 12.2(18)SXF5 and later releases, you can configure WS-X6708-10GE ports to use received DSCP values for ingress LAN port classification and congestion avoidance (see the “Configuring
DSCP-Based Queue Mapping” section on page 42-98)
In Releases earlier than Release 12.2(18)SXF5, ingress LAN port classification, marking, and congestion avoidance use Layer 2 CoS values only.
The following sections describe classification and marking at trusted and untrusted ingress ports:
Classification and Marking at Untrusted Ingress Ports, page 42-16
Ingress Classification and Marking at Trusted Ports, page 42-16
Classification and Marking at Untrusted Ingress Ports
PFC QoS Layer 2 remarking marks all frames received through untrusted ports with the port CoS value (the default is zero).
To map the port CoS value that was applied to untrusted ingress traffic to the initial internal DSCP value, configure a trust CoS policy map that matches the ingress traffic.
Ingress Classification and Marking at Trusted Ports
You should configure ports to trust only if they receive traffic that carries valid QoS labels. QoS uses the received QoS labels as the basis of initial internal DSCP value. After the traffic enters the router, you can apply a different trust state to traffic with a policy map. For example, traffic can enter the router through a trust CoS port, and then you can use a policy map to trust IP precedence or DSCP, which uses the trusted value as the basis of the initial internal DSCP value, instead of the QoS label that was trusted at the port.
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These sections describe classification and marking at trusted ingress ports:
Ingress Classification and Marking at Trust CoS LAN Ports, page 42-17
Ingress Classification and Marking at Trust IP Precedence Ports, page 42-17
Ingress Classification and Marking at Trust DSCP Ports, page 42-17
Ingress Classification and Marking at Trust CoS LAN Ports
You should configure LAN ports to trust CoS only if they receive traffic that carries valid Layer 2 CoS.
When an ISL frame enters the router through a trusted ingress LAN port, PFC QoS accepts the three least significant bits in the User field as a CoS value. When an 802.1Q frame enters the router through a trusted ingress LAN port, PFC QoS accepts the User Priority bits as a CoS value. PFC QoS Layer 2 remarking marks all traffic received in untagged frames with the ingress port CoS value.
On ports configured to trust CoS, PFC QoS does the following:
PFC QoS maps the received CoS value in tagged trust CoS traffic to the initial internal DSCP value.
PFC QoS maps the ingress port CoS value applied to untagged trusted traffic to the initial internal
DSCP value.
PFC QoS enables the CoS-based ingress queues and thresholds to provide congestion avoidance.
See the “Understanding Port-Based Queue Types” section on page 42-22 for more information about ingress queues and thresholds.
Understanding How PFC QoS Works
Ingress Classification and Marking at Trust IP Precedence Ports
You should configure ports to trust IP precedence only if they receive traffic that carries valid Layer 3 IP precedence. For traffic from trust IP precedence ports, PFC QoS maps the received IP precedence value to the initial internal DSCP value. Because the ingress port queues and thresholds use Layer 2 CoS, PFC QoS does not implement ingress port congestion avoidance on ports configured to trust IP precedence. PFC does not mark any traffic on ingress ports configured to trust IP precedence.
Ingress Classification and Marking at Trust DSCP Ports
You should configure ports to trust DSCP only if they receive traffic that carries valid Layer 3 DSCP.
In Release 12.2(18)SXF5 and later releases, you can enable DSCP-based ingress queues and thresholds on WS-X6708-10GE ports to provide congestion avoidance (see the “Configuring DSCP-Based Queue
Mapping” section on page 42-98).
In releases earlier than Release 12.2(18)SXF5, the ingress port queues and thresholds use only Layer 2 CoS, and PFC QoS does not implement ingress port congestion avoidance on ports configured to trust DSCP.
For traffic from trust DSCP ports, PFC QoS uses the received DSCP value as the initial internal DSCP value. PFC QoS does not mark any traffic on ingress ports configured to trust received DSCP.

Classification and Marking at Ingress OSM Ports

PFC QoS associates CoS zero with all traffic received through ingress OSM ports. You can configure ingress OSM port trust states that can be used by the PFC to set IP precedence or DSCP values and the CoS value. You can configure the trust state of each ingress OSM port as follows:
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Untrusted (default)
Trust IP precedence
Trust DSCP
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Understanding How PFC QoS Works
Trust CoS (CoS is always zero for POS and ATM OSM ports because the port CoS value is not
configurable on POS and ATM OSM ports.)

Classification and Marking on the PFC Using Service Policies and Policy Maps

PFC QoS supports classification and marking with service policies that attach one policy map to these interface types to apply ingress PFC QoS:
Each ingress port (except FlexWAN interfaces)
Each EtherChannel port-channel interface
Each VLAN interface
With a PFC3, you can attach one policy map to each Layer 3 interface (except FlexWAN interfaces) to apply egress PFC QoS.
Each policy map can contain multiple policy-map classes. You can configure a separate policy-map class for each type of traffic handled by the interface. There are two ways to configure filtering in policy-map classes:
Access control lists (ACLs)
Class-map match commands for IP precedence and DSCP values
Policy-map classes specify actions with the following optional commands:
Policy-map set commands—For untrusted traffic or if ignore port trust is enabled, PFC QoS can use
configured IP precedence or DSCP values as the final internal DSCP value. The “IP Precedence and
DSCP Values” section on page 42-55 shows the bit values for IP precedence and DSCP.
Policy-map class trust commands—PFC QoS applies the policy-map class trust state to matched
ingress traffic, which then uses the trusted value as the basis of its initial internal DSCP value, instead of the QoS label that was trusted at the port (if any). In a policy map, you can trust CoS, IP
precedence, or DSCP.
Note A trust CoS policy map cannot restore received CoS in traffic from untrusted ports. Traffic
from untrusted ports always has the port CoS value.
Aggregate and microflow policers—PFC QoS can use policers to either mark or drop both
conforming and nonconforming traffic.
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Classification and Marking on the MSFC

PFC QoS sends IP traffic to the MSFC with the final internal DSCP values. CoS is equal to IP precedence in all traffic sent from the MSFC to egress ports.
Figure 42-9 Marking with PFC2 or PFC3 and MSFC2, MSFC2A, or MSFC3
From PFC
Multilayer Switch Feature Card (MSFC) marking
Understanding How PFC QoS Works

Policers

IP traffic
from PFC?
No
Route
traffic
To egress
port
Note Traffic that is Layer 3 switched on the PFC does not go through the MSFC and retains the CoS value
Ye s
CoS =
all traffic
Write ToS
byte into
packet
144800
IP precedence for
(not configurable)
assigned by the PFC.
These sections describe policers:
Overview of Policers, page 42-19
Aggregate Policers, page 42-20
Microflow Policers, page 42-21

Overview of Policers

Policing allows you to rate limit incoming and outgoing traffic so that it adheres to the traffic forwarding rules defined by the QoS configuration. Sometimes these configured rules for how traffic should be forwarded through the system are referred to as a contract. If the traffic does not adhere to this contract, it is marked down to a lower DSCP value or dropped.
Policing does not buffer out-of-profile packets. As a result, policing does not affect transmission delay. In contrast, traffic shaping works by buffering out-of-profile traffic, which moderates the traffic bursts. (PFC QoS does not support shaping.)
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The PFC2 supports only ingress PFC QoS, which includes ingress policing. The PFC3 supports both ingress and egress PFC QoS, which includes ingress and egress policing. Traffic shaping is supported on some WAN modules. For more information about traffic shaping on the OSM and FlexWAN modules, refer to the OSM and FlexWAN documentation at this location:
http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/cfgnotes/index.htm
Note Policers can act on ingress traffic per-port or per-VLAN. With a PFC3, for egress traffic, the policers can
act per-VLAN only.
You can create policers to do the following:

Aggregate Policers

PFC QoS applies the bandwidth limits specified in an aggregate policer cumulatively to all flows in matched traffic. For example, if you configure an aggregate policer to allow 1 Mbps for all TFTP traffic flows on VLAN 1 and VLAN 3, it limits the TFTP traffic for all flows combined on VLAN 1 and VLAN 3 to 1 Mbps.
Chapter 42 Configuring PFC QoS
Mark traffic
Limit bandwidth utilization and mark traffic
You define per-interface aggregate policers in a policy map class with the police command. If you
attach a per-interface aggregate policer to multiple ingress ports, it polices the matched traffic on each ingress port separately.
You create named aggregate policers with the mls qos aggregate-policer command. If you attach a
named aggregate policer to multiple ingress ports, it polices the matched traffic from all the ingress ports to which it is attached.
Aggregate policing works independently on each DFC-equipped switching module and
independently on the PFC, which supports any non-DFC-equipped switching modules. Aggregate policing does not combine flow statistics from different DFC-equipped switching modules. You can display aggregate policing statistics for each DFC-equipped switching module and for the PFC and any non-DFC-equipped switching modules supported by the PFC.
Each PFC or DFC polices independently, which might affect QoS features being applied to traffic
that is distributed across the PFC and any DFCs. Examples of these QoS feature are:
Policers applied to a port channel interface.
Policers applied to a switched virtual interface.
Egress policers applied to either a Layer 3 interface or an SVI. Note that PFC QoS performs egress policing decisions at the ingress interface, on the PFC or ingress DFC.
Policers affected by this restriction deliver an aggregate rate that is the sum of all the independent policing rates.
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Microflow Policers

PFC QoS applies the bandwidth limit specified in a microflow policer separately to each flow in matched traffic. For example, if you configure a microflow policer to limit the TFTP traffic to 1 Mbps on VLAN 1 and VLAN 3, then 1 Mbps is allowed for each flow in VLAN 1 and 1 Mbps for each flow in VLAN 3. In other words, if there are three flows in VLAN 1 and four flows in VLAN 3, the microflow policer allows each of these flows 1 Mbps.
You can configure PFC QoS to apply the bandwidth limits in a microflow policer as follows:
Understanding How PFC QoS Works
You can create microflow policers with up to 63 different rate and burst parameter combinations.
You create microflow policers in a policy map class with the police flow command.
You can configure a microflow policer to use only source addresses, which applies the microflow
policer to all traffic from a source address regardless of the destination addresses.
You can configure a microflow policer to use only destination addresses, which applies the
microflow policer to all traffic to a destination address regardless of the source addresses.
For MAC-Layer microflow policing, PFC QoS considers MAC-Layer traffic with the same protocol
and the same source and destination MAC-Layer addresses to be part of the same flow, including traffic with different EtherTypes. With a PFC3, you can configure MAC ACLs to filter IPX traffic.
With a PFC2, you can configure IPX ACLs to filter IPX traffic. For IPX microflow policing,
PFC QoS considers IPX traffic with the same source network, destination network, and destination node to be part of the same flow, including traffic with different source nodes or source sockets.
By default, microflow policers only affect traffic routed by the MSFC. To enable microflow policing
of other traffic, including traffic in bridge groups, enter the mls qos bridged command. With a PFC2, you must enable bridged mircoflow policing for routed traffic as well.
With a PFC3, you cannot apply microflow policing to ARP traffic.
You cannot apply microflow policing to IPv6 multicast traffic.
You can include both an aggregate policer and a microflow policer in each policy map class to police a flow based on both its own bandwidth utilization and on its bandwidth utilization combined with that of other flows.
Note If traffic is both aggregate and microflow policed, then the aggregate and microflow policers must both
be in the same policy-map class and each must use the same conform-action and exceed-action keyword option: drop, set-dscp-transmit, set-prec-transmit, or transmit.
For example, you could create a microflow policer with a bandwidth limit suitable for individuals in a group, and you could create a named aggregate policer with bandwidth limits suitable for the group as a whole. You could include both policers in policy map classes that match the group’s traffic. The combination would affect individual flows separately and the group aggregately.
For policy map classes that include both an aggregate and a microflow policer, PFC QoS responds to an out-of-profile status from either policer and, as specified by the policer, applies a new DSCP value or drops the packet. If both policers return an out-of-profile status, then if either policer specifies that the packet is to be dropped, it is dropped; otherwise, PFC QoS applies a marked-down DSCP value.
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Note To avoid inconsistent results, ensure that all traffic policed by the same aggregate policer has the same
trust state.
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Understanding How PFC QoS Works
With a PFC3, policing uses the Layer 2 frame size. With a PFC2, policing uses the Layer 3 packet size. You specify the bandwidth utilization limit as a committed information rate (CIR). You can also specify a higher peak information rate (PIR). Packets that exceed a rate are “out of profile” or “nonconforming.”
In each policer, you specify if out-of-profile packets are to be dropped or to have a new DSCP value applied to them (applying a new DSCP value is called “markdown”). Because out-of-profile packets do not retain their original priority, they are not counted as part of the bandwidth consumed by in-profile packets.
If you configure a PIR, the PIR out-of-profile action cannot be less severe than the CIR out-of-profile action. For example, if the CIR out-of-profile action is to mark down the traffic, then the PIR out-of-profile action cannot be to transmit the traffic.
For all policers, PFC QoS uses a configurable global table that maps the internal DSCP value to a marked-down DSCP value. When markdown occurs, PFC QoS gets the marked-down DSCP value from the table. You cannot specify marked-down DSCP values in individual policers.
Note Policing with the conform-action transmit keywords supersedes the ingress LAN port trust state
of matched traffic with trust DSCP or with the trust state defined by a trust policy-map class command.
Chapter 42 Configuring PFC QoS
By default, the markdown table is configured so that no markdown occurs: the marked-down DSCP
values are equal to the original DSCP values. To enable markdown, configure the table appropriately for your network.
When you apply both ingress policing and egress policing to the same traffic, both the input policy
and the output policy must either mark down traffic or drop traffic. PFC QoS does not support ingress markdown with egress drop or ingress drop with egress markdown.

Understanding Port-Based Queue Types

Port-based queue types are determined by the ASICs that control the ports. The following sections describe the queue types, drop thresholds, and buffers that are supported on the Cisco 7600 series router LAN modules:
Ingress and Egress Buffers and Layer 2 CoS-Based Queues, page 42-22
Ingress Queue Types, page 42-24
Egress Queue Types, page 42-25
Module to Queue Type Mappings, page 42-26

Ingress and Egress Buffers and Layer 2 CoS-Based Queues

42-22
The Ethernet LAN module port ASICs have buffers that are divided into a fixed number of queues. When
congestion avoidance is enabled, PFC QoS uses the traffic’s Layer 2 CoS value to assign traffic to the
queues. The buffers and queues store frames temporarily as they transit the switch. PFC QoS allocates the port ASIC memory as buffers for each queue on each port.
The Cisco 7600 series router LAN modules support the following types of queues:
Standard queues
Strict-priority queues
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The Cisco 7600 series router LAN modules support the following types of scheduling algorithms between queues:
Shaped round robin (SRR)—SRR allows a queue to use only the allocated bandwidth.
Deficit weighted round robin (DWRR)—DWRR keeps track of any lower-priority queue
under-transmission caused by traffic in a higher-priority queue and compensates in the next round.
Weighted Round Robin (WRR)—WRR does not explicitly reserve bandwidth for the queues. Instead,
the amount of bandwidth assigned to each queue is user configurable. The percentage or weight allocated to a queue defines the amount of bandwidth allocated to the queue.
Strict-priority queueing—Strict priority queueing allows delay-sensitive data such as voice to be
dequeued and sent before packets in other queues are dequeued, giving delay-sensitive data preferential treatment over other traffic. The router services traffic in the strict-priority transmit queue before servicing the standard queues. After transmitting a packet from a standard queue, the switch checks for traffic in the strict-priority queue. If the switch detects traffic in the strict-priority queue, it suspends its service of the standard queue and completes service of all traffic in the strict-priority queue before returning to the standard queue.
The Cisco 7600 series router LAN modules provides congestion avoidance with these types of thresholds within a queue:
Weighted Random Early Detection (WRED)—On ports with WRED drop thresholds, frames with a
given QoS label are admitted to the queue based on a random probability designed to avoid buffer congestion. The probability of a frame with a given QoS label being admitted to the queue or discarded depends on the weight and threshold assigned to that QoS label.
For example, if CoS 2 is assigned to queue 1, threshold 2, and the threshold 2 levels are 40 percent (low) and 80 percent (high), then frames with CoS 2 will not be dropped until queue 1 is at least 40 percent full. As the queue depth approaches 80 percent, frames with CoS 2 have an increasingly higher probability of being discarded rather than being admitted to the queue. Once the queue is over 80 percent full, all CoS 2 frames are dropped until the queue is less than 80 percent full. The frames the switch discards when the queue level is between the low and high thresholds are picked out at random, rather than on a per-flow basis or in a FIFO manner. This method works well with protocols such as TCP that can adjust to periodic packet drops by backing off and adjusting their transmission window size.
Understanding How PFC QoS Works
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Tail-drop thresholds—On ports with tail-drop thresholds, frames with a given QoS label are
admitted to the queue until the drop threshold associated with that QoS label is exceeded; subsequent frames of that QoS label are discarded until the threshold is no longer exceeded. For example, if CoS 1 is assigned to queue 1, threshold 2, and the threshold 2 watermark is 60 percent, then frames with CoS 1 will not be dropped until queue 1 is 60 percent full. All subsequent CoS 1 frames will be dropped until the queue is less than 60 percent full. With some port types, you can configure the standard receive queue to use both a tail-drop and a WRED-drop threshold by mapping a CoS value to the queue or to the queue and a threshold. The switch uses the tail-drop threshold for traffic carrying CoS values mapped only to the queue. The switch uses WRED-drop thresholds for traffic carrying CoS values mapped to the queue and a threshold. All LAN ports of the same type use the same drop-threshold configuration.
Note In Release 12.2(18)SXF5 and later releases, you can enable DSCP-based queues and thresholds on
WS-X6708-10GE ports (see the “Configuring DSCP-Based Queue Mapping” section on page 42-98).
The combination of multiple queues and the scheduling algorithms associated with each queue allows the switch to provide congestion avoidance.
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Figure 42-10 illustrates the drop thresholds for a 1q4t ingress LAN port. Drop thresholds in other
configurations function similarly.
Figure 42-10 Receive Queue Drop Thresholds
Reserved for
CoS 6 and 7
Reserved for CoS 4 and higher
Reserved for CoS 2 and higher
Available for traffic with any CoS value
Drop threshold 4: 100%
Drop threshold 3: 80%
Drop threshold 2: 60%
Drop threshold 1: 50%
Chapter 42 Configuring PFC QoS
C
o
S
6
a
n
C
o
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4
a
C
o
S
C
o
S
0
a
n
d
n
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a
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d
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5
Traffic is dropped
100% available for CoS 6 and 7
80% available for CoS 4 and 5
60% available for CoS 2 and 3
50% available for CoS 0 and 1

Ingress Queue Types

To see the queue structure of a LAN port, enter the show queueing interface {ethernet | fastethernet | gigabitethernet | tengigabitethernet} slot/port | include type command. The command displays one of
the following architectures:
1q2t indicates one standard queue with one configurable tail-drop threshold and one
nonconfigurable tail-drop threshold.
1q4t indicates one standard queue with four configurable tail-drop thresholds.
1q8t indicates one standard queue with eight configurable tail-drop thresholds.
2q8t indicates two standard queues, each with eight configurable tail-drop thresholds.
8q4t indicates eight standard queues, each with four thresholds, each configurable as either
WRED-drop or tail-drop.
8q8t indicates eight standard queues, each with eight thresholds, each configurable as either
WRED-drop or tail-drop.
Receive queue
(Default values shown)
26249
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1p1q4t indicates:
One strict-priority queue
One standard queue with four configurable tail-drop thresholds.
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1p1q0t indicates:
1p1q8t indicates the following:

Egress Queue Types

To see the queue structure of an egress LAN port, enter the show queueing interface {ethernet | fastethernet | gigabitethernet | tengigabitethernet} slot/port | include type command.
The command displays one of the following architectures:
2q2t indicates two standard queues, each with two configurable tail-drop thresholds.
Understanding How PFC QoS Works
One strict-priority queue
One standard queue with no configurable threshold (effectively a tail-drop threshold at 100 percent).
One strict-priority queue
One standard queue with these thresholds:
—Eight thresholds, each configurable as either WRED-drop or tail-drop
—One non configurable (100 percent) tail-drop threshold
1p2q2t indicates the following:
One strict-priority queue
Two standard queues, each with two configurable WRED-drop thresholds
1p3q1t indicates the following:
One strict-priority queue
Three standard queues with these thresholds:
—One threshold configurable as either WRED-drop or tail-drop
—One nonconfigurable (100 percent) tail-drop threshold
1p2q1t indicates the following:
One strict-priority queue
Two standard queues with these thresholds:
—One WRED-drop threshold
—One non-configurable (100 percent) tail-drop threshold
1p3q8t indicates the following:
One strict-priority queue
Three standard queues, each with eight thresholds, each threshold configurable as either WRED-drop or tail-drop
1p7q4t indicates the following:
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Seven standard queues, each with four thresholds, each threshold configurable as either WRED-drop or tail-drop
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1p7q8t indicates the following:
One strict-priority queue
Seven standard queues, each with eight thresholds, each threshold configurable as either WRED-drop or tail-drop

Module to Queue Type Mappings

The following tables show the module to queue structure mapping:
Supervisor Engine Module QoS Queue Structures
Ethernet and Fast Ethernet Module Queue Structures
Gigabit and 10/100/1000 Ethernet Modules
10 Gigabit Ethernet Modules
Table 42-2 Supervisor Engine Module QoS Queue Structures
Chapter 42 Configuring PFC QoS
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
Supervisor Engines
Ingress Queue and Drop Thresholds
Ingress Queue Scheduler
WS-SUP720 1p1q4t 1p2q2t WRR 512 KB 73 KB 439 KB
WS-SUP720-3B
WS-SUP720-3BXL
WS-SUP32-10GE 2q8t WRR 1p3q8t DWRR
10 Gigabit Ethernet ports 193 MB 105 MB 88 MB
SRR
Gigabit Ethernet port 17.7 MB 9.6 MB 8.1 MB
WS-SUP32-GE 17.7 MB 9.6 MB 8.1 MB
WS-X6K-S2U-MSFC2 1p1q4t 1p2q2t WRR 512 KB 73 KB 439 KB
WS-X6K-S2-MSFC2
WS-X6K-S2-PFC2
Table 42-3 Ethernet and Fast Ethernet Module Queue Structures
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
Modules
Ingress Queue and Drop Thresholds
Ingress Queue Scheduler
WS-X6524-100FX-MM 1p1q0t 1p3q1t DWRR 1,116 KB 28 KB 1,088 KB
WS-X6548-RJ-21
WS-X6548-RJ-45
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Table 42-3 Ethernet and Fast Ethernet Module Queue Structures (continued)
Understanding How PFC QoS Works
Modules
Ingress Queue and Drop Thresholds
Ingress Queue Scheduler
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
WS-X6324-100FX-MM 1q4t 2q2t WRR 128 KB 16 KB 112 KB
WS-X6324-100FX-SM
WS-X6348-RJ-45
WS-X6348-RJ-45V
WS-X6348-RJ-21V
WS-X6224-100FX-MT 64 KB 8 KB 56 KB
WS-X6248-RJ-45
WS-X6248-TEL
WS-X6248A-TEL 128 KB 16 KB 112 KB
WS-X6148-RJ-45
WS-X6148-RJ-45V
WS-X6148-45AF
WS-X6148-RJ-21
WS-X6148-RJ-21V
WS-X6148-21AF
WS-X6148X2-RJ-45 1p1q0t 1p3q1t DWRR 1,116 KB 28 KB 1,088 KB
WS-X6148X2-45AF
WS-X6024-10FL-MT 1q4t 2q2t WRR 64 KB 8 KB 56 KB
Table 42-4 Gigabit and 10/100/1000 Ethernet Modules
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
Modules
Ingress Queue and Drop Thresholds
Ingress Queue Scheduler
WS-X6816-GBIC 1p1q4t 1p2q2t WRR 512 KB 73 KB 439 KB
WS-X6748-GE-TX with DFC3 2q8t WRR 1p3q8t DWRR 1.3 MB 166 KB 1.2 MB
WS-X6748-GE-TX with CFC 1q8t
WS-X6748-SFP with DFC3 2q8t WRR
WS-X6748-SFP with CFC 1q8t
WS-X6724-SFP with DFC3 2q8t WRR
WS-X6724-SFP with CFC 1q8t
WS-X6548-GE-TX 1q2t 1p2q2t WRR 1.4 MB 185 KB 1.2 MB
WS-X6548V-GE-TX
WS-X6548-GE-45AF
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Table 42-4 Gigabit and 10/100/1000 Ethernet Modules
Chapter 42 Configuring PFC QoS
Modules
Ingress Queue and Drop Thresholds
Ingress Queue Scheduler
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
WS-X6516-GBIC 1p1q4t 1p2q2t WRR 512 KB 73 KB 439 KB
WS-X6516A-GBIC WRR 1 MB 135 KB 946 KB
WS-X6516-GE-TX WRR 512 KB 73 KB 439 KB
WS-X6408-GBIC 1q4t 2q2t WRR 80 KB 432 KB
WS-X6408A-GBIC 1p1q4t — 1p2q2t WRR 73 KB 439 KB
WS-X6416-GBIC
WS-X6416-GE-MT
WS-X6316-GE-TX
WS-X6148-GE-TX 1q2t 1.4 MB 185 KB 1.2 MB
WS-X6148V-GE-TX
WS-X6148-GE-45AF
Table 42-5 10 Gigabit Ethernet Modules
Ingress
Modules
Queue and Drop Thresholds
Ingress Queue Scheduler
WS-X6708-10GE 8q4t DWRR 1p7q4t DWRR
Egress Queue and Drop Thresholds
Egress Queue Scheduler
Total Buffer Size
Ingress Buffer Size
Egress Buffer Size
198 MB 108 MB 90 MB
SRR
WS-X6704-10GE with DFC3 8q8t WRR 1p7q8t DWRR 16 MB 2 MB 14 MB
WS-X6704-10GE with CFC 1q8t
WS-X6502-10GE 1p1q8t 1p2q1t DWRR 64.2 MB 256 KB 64 MB
WS-X6501-10GEX4
PFC QoS Default Configuration
These sections describe the PFC QoS default configuration:
PFC QoS Global Settings, page 42-29
Default Values With PFC QoS Enabled, page 42-30
Default Values With PFC QoS Disabled, page 42-49
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PFC QoS Global Settings

The following global PFC QoS settings apply:
Feature Default Value
PFC QoS global enable state Disabled
PFC QoS port enable state Enabled when PFC QoS is globally enabled
Port CoS value 0
Microflow policing Enabled
IntraVLAN microflow policing Disabled
Port-based or VLAN-based PFC QoS Port-based
Received CoS to initial internal DSCP map (initial internal DSCP set from received CoS values)
Received IP precedence to initial internal DSCP map (initial internal DSCP set from received IP precedence values)
Final internal DSCP to egress CoS map (egress CoS set from final internal DSCP values)
Marked-down DSCP from DSCP map Marked-down DSCP value equals original
Policers None
Policy maps None
Protocol-independent MAC ACL filtering Disabled
VLAN-based MAC ACL QoS filtering Disabled
PFC QoS Default Configuration
CoS 0 = DSCP 0 CoS 1 = DSCP 8 CoS 2 = DSCP 16 CoS 3 = DSCP 24 CoS 4 = DSCP 32 CoS 5 = DSCP 40 CoS 6 = DSCP 48 CoS 7 = DSCP 56
IP precedence 0 = DSCP 0 IP precedence 1 = DSCP 8 IP precedence 2 = DSCP 16 IP precedence 3 = DSCP 24 IP precedence 4 = DSCP 32 IP precedence 5 = DSCP 40 IP precedence 6 = DSCP 48 IP precedence 7 = DSCP 56
DSCP 0–7 = CoS 0 DSCP 8–15 = CoS 1 DSCP 16–23 = CoS 2 DSCP 24–31 = CoS 3 DSCP 32–39 = CoS 4 DSCP 40–47 = CoS 5 DSCP 48–55 = CoS 6 DSCP 56–63 = CoS 7
DSCP value (no markdown)
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Default Values With PFC QoS Enabled

These sections list the default values that apply when PFC QoS is enabled:
Receive-Queue Limits, page 42-30
Transmit-Queue Limit s, page 42-30
Bandwidth Allocation Ratios, page 42-31
Default Drop-Threshold Percentages and CoS Value Mappings, page 42-31
Note The ingress LAN port trust state defaults to untrusted with QoS enabled.

Receive-Queue Limits

Feature Default Value
2q8t Low priority: 80%
High priority: 20%
8q4t Low priority: 80%
Intermediate queues: 0%
High priority: 20%
8q8t Lowest priority: 80%
Intermediate queues: 0%
Highest priority: 20%
Chapter 42 Configuring PFC QoS

Transmit-Queue Limit s

Feature Default Value
2q2t Low priority: 80%
1p2q2t Low priority: 70%
1p2q1t Low priority: 70%
1p3q8t Low priority: 50%
High priority: 20%
High priority: 15%
Strict priority 15%
High priority: 15%
Strict priority 15%
Medium priority: 20%
High priority: 15%
Strict priority 15%
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Feature Default Value
1p7q4t Standard queue 1 (lowest priority): 50%
1p7q8t Standard queue 1 (lowest priority): 50%

Bandwidth Allocation Ratios

PFC QoS Default Configuration
Standard queue 2: 20%
Standard queue 3: 15%
Standard queues 4 through 7: 0%
Strict priority 15%
Standard queue 2: 20%
Standard queue 3: 15%
Standard queues 4 through 7: 0%
Strict priority 15%
Feature Default Value
2q8t 90:10
8q4t 90:0:0:0:0:0:0:10
8q8t 90:0:0:0:0:0:0:10
1p3q8t 22:33:45
1p7q4t 100:150:200:0:0:0:0:0
1p7q8t 22:33:45:0:0:0:0
1p2q1t 100:255
2q2t, 1p2q2t, and 1p2q1t 5:255
1p3q1t 100:150:255

Default Drop-Threshold Percentages and CoS Value Mappings

The following tables list the default drop-thresholds values and CoS mappings for different queue types:
1q2t Receive Queues, page 42-32
1q4t Receive Queues, page 42-32
1p1q4t Receive Queues, page 42-33
1p1q0t Receive Queues, page 42-33
1p1q8t Receive Queues, page 42-34
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2q8t Receive Queues, page 42-36
8q4t Receive Queues, page 42-37
8q8t Receive Queues, page 42-41
2q2t Transmit Queues, page 42-41
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Note The receive queue values shown are the values in effect when the port is configured to trust CoS or DSCP.
1q2t Receive Queues
Chapter 42 Configuring PFC QoS
1p2q2t Transmit Queues, page 42-42
1p3q8t Transmit Queues, page 42-43
1p7q4t Transmit Queues, page 42-44
1p7q8t Transmit Queues, page 42-47
1p3q1t Transmit Queues, page 42-48
1p2q1t Transmit Queues, page 42-49
When the port is untrusted, the receive queue values are the same as when QoS is globally disabled.
Feature Default Value
Standard receive queue Threshold 1 CoS 0, 1, 2, 3, and 4
Tail-drop 80%
WRED-drop Not supported
Threshold 2 CoS 5, 6, and 7
Tail-drop 100% (not configurable)
WRED-drop Not supported
1q4t Receive Queues
Feature Default Value
Standard receive queue Threshold 1 CoS 0 and 1
Tail-drop 50%
WRED-drop Not supported
Threshold 2 CoS 2 and 3
Tail-drop 60%
WRED-drop Not supported
Threshold 3 CoS 4 and 5
Tail-drop 80%
WRED-drop Not supported
Threshold 4 CoS 6 and 7
Tail-drop 100%
WRED-drop Not supported
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1p1q4t Receive Queues
PFC QoS Default Configuration
Feature Default Value
Standard receive queue Threshold 1 CoS 0 and 1
Tail-drop 50%
WRED-drop Not supported
Threshold 2 CoS 2 and 3
Tail-drop 60%
WRED-drop Not supported
Threshold 3 CoS 4
Tail-drop 80%
WRED-drop Not supported
Threshold 4 CoS 6 and 7
Tail-drop 100%
WRED-drop Not supported
Strict-priority receive queue CoS 5
Tail-drop 100% (nonconfigurable)
1p1q0t Receive Queues
Feature Default Value
Standard receive queue CoS 0, 1, 2, 3, 4, 6, and 7
Tail-drop 100% (nonconfigurable)
WRED-drop Not supported
Strict-priority receive queue CoS 5
Tail-drop 100% (nonconfigurable)
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Feature Default Value
Standard receive queue Threshold 1 CoS 0
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 1
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 3 CoS 2
Tail-drop Disabled; 80%
WRED-drop Enabled; 50% low, 80% high
Threshold 4 CoS 3
Tail-drop Disabled; 80%
WRED-drop Enabled; 50% low, 80% high
Threshold 5 CoS 4
Tail-drop Disabled; 90%
WRED-drop Enabled; 60% low, 90% high
Threshold 6 CoS 6
Tail-drop Disabled; 90%
WRED-drop Enabled; 60% low, 90% high
Threshold 7 CoS 7
Tail-drop Disabled; 100%
WRED-drop Enabled;70% low, 100% high
Strict-priority receive queue CoS 5
Tail-drop 100% (nonconfigurable)
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1q8t Receive Queues
PFC QoS Default Configuration
Feature Default Value
Standard receive queue Threshold 1 CoS 0
Tail-drop 50%
WRED-drop Not supported
Threshold 2 CoS None
Tail-drop 50%
WRED-drop Not supported
Threshold 3 CoS 1, 2, 3, 4
Tail-drop 60%
WRED-drop Not supported
Threshold 4 CoS None
Tail-drop 60%
WRED-drop Not supported
Threshold 5 CoS 6 and 7
Tail-drop 80%
WRED-drop Not supported
Threshold 6 CoS None
Tail-drop 80%
WRED-drop Not supported
Threshold 7 CoS 5
Tail-drop 100%
WRED-drop Not supported
Threshold 8 CoS None
Tail-drop 100%
WRED-drop Not supported
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2q8t Receive Queues
Chapter 42 Configuring PFC QoS
Feature Default Value
Standard receive queue 1 (low priority)
Threshold 1 CoS 0 and 1
Tail-drop 70%
WRED-drop Not supported
Threshold 2 CoS 2 and 3
Tail-drop 80%
WRED-drop Not supported
Threshold 3 CoS 4
Tail-drop 90%
WRED-drop Not supported
Threshold 4 CoS 6 and 7
Tail-drop 100%
WRED-drop Not supported
Thresholds 5–8 CoS None
Tail-drop 100%
WRED-drop Not supported
Standard receive queue 2 (high priority)
Threshold 1 CoS 5
Tail-drop 100%
WRED-drop Not supported
Thresholds 2–8 CoS None
Tail-drop 100%
WRED-drop Not supported
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8q4t Receive Queues
PFC QoS Default Configuration
Feature Default Value
Standard receive queue 1 (lowest priority)
Threshold 1 CoS 0 and 1
DSCP 0–9, 11, 13, 15–17, 19, 21, 23, 25,
27, 29, 31, 33, 39, 41–45, 47
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 2 and 3
DSCP
Tail-drop Disabled; 80%
WRED-drop Enabled; 40% low, 80% high
Threshold 3 CoS 4
DSCP
Tail-drop Disabled; 90%
WRED-drop Enabled; 50% low, 90% high
Threshold 4 CoS 6 and 7
DSCP
Tail-drop Disabled; 100%
WRED-drop Enabled; 50% low, 100% high
Standard receive queue 2 (intermediate priority)
Threshold 1 CoS None
DSCP 14
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP 12
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP 10
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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Feature (continued) Default Value
Standard receive queue 3 (intermediate priority)
Standard receive queue 4 (intermediate priority)
Chapter 42 Configuring PFC QoS
Threshold 1 CoS None
DSCP 22
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP 20
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP 18
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 1 CoS None
DSCP 24 and 30
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP 28
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP 26
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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Feature (continued) Default Value
Standard receive queue 5 (intermediate priority)
Standard receive queue 6 (intermediate priority)
PFC QoS Default Configuration
Threshold 1 CoS None
DSCP 32, 34–38
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 1 CoS None
DSCP 48–63
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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Feature (continued) Default Value
Standard receive queue 7 (intermediate priority)
Standard receive queue 8 (high priority)
Chapter 42 Configuring PFC QoS
Threshold 1 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 1 CoS 5
DSCP 40 and 46
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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PFC QoS Default Configuration
Feature Default Value
Standard receive queue 1 (lowest priority)
Threshold 1 CoS 0 and 1
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 2 and 3
Tail-drop Disabled; 80%
WRED-drop Enabled; 40% low, 80% high
Threshold 3 CoS 4
Tail-drop Disabled; 90%
WRED-drop Enabled; 50% low, 90% high
Threshold 4 CoS 6 and 7
Tail-drop Disabled; 100%
WRED-drop Enabled; 50% low, 100% high
Thresholds 5–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 50% low, 100% high
Standard receive queues 2–7 (intermediate priorities)
Thresholds 1–8 CoS None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Standard receive queue 8 (highest priority)
Threshold 1 CoS 5
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Thresholds 2–8 CoS None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
2q2t Transmit Queues
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Feature Default Value
Standard transmit queue 1 (low priority)
Threshold 1 CoS 0 and 1
Tail-drop 80%
WRED-drop Not supported
Threshold 2 CoS 2 and 3
Tail-drop 100%
WRED-drop Not supported
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Feature Default Value
Standard transmit queue 2 (high priority)
Threshold 1 CoS 4 and 5
Tail-drop 80%
WRED-drop Not supported
Threshold 2 CoS 6 and 7
Tail-drop 100%
WRED-drop Not supported
Feature Default Value
Standard transmit queue 1 (low priority)
Threshold 1 CoS 0 and 1
Tail-drop Not supported
WRED-drop 40% low, 70% high
Threshold 2 CoS 2 and 3
Tail-drop Not supported
WRED-drop 70% low, 100% high
Standard transmit queue 2 (high priority)
Threshold 1 CoS 4 and 6
Tail-drop Not supported
WRED-drop 40% low, 70% high
Threshold 2 CoS 7
Tail-drop Not supported
WRED-drop 70% low, 100% high
Strict-priority transmit queue CoS 5
Tail-drop 100% (nonconfigurable)
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1p3q8t Transmit Queues
PFC QoS Default Configuration
Feature Default Value
Standard transmit queue 1 (lowest priority)
Threshold 1 CoS 0
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 1
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 3 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 4 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 5–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 50% low, 100% high
Standard transmit queue 2 (medium priority)
Threshold 1 CoS 2
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 3 and 4
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 3–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Standard transmit queue 3 (high priority)
Threshold 1 CoS 6 and 7
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 2–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Strict-priority transmit queue CoS 5
Tail-drop 100% (nonconfigurable)
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Feature Default Value
Standard receive queue 1 (lowest priority)
Threshold 1 CoS 0 and 1
DSCP 0–9, 11, 13, 15–17, 19, 21, 23, 25,
27, 29, 31, 33, 39, 41–45, 47
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 2 and 3
DSCP
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 3 CoS 4
DSCP
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 4 CoS 6 and 7
DSCP
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Standard receive queue 2 (intermediate priority)
Threshold 1 CoS None
DSCP 14
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS None
DSCP 12
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 3 CoS None
DSCP 10
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
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Feature (continued) Default Value
Standard receive queue 3 (intermediate priority)
Standard receive queue 4 (intermediate priority)
PFC QoS Default Configuration
Threshold 1 CoS None
DSCP 22
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 2 CoS None
DSCP 20
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 3 CoS None
DSCP 18
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 1 CoS None
DSCP 24 and 30
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP 28
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP 26
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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Feature (continued) Default Value
Standard receive queue 5 (intermediate priority)
Standard receive queue 6 (intermediate priority)
Chapter 42 Configuring PFC QoS
Threshold 1 CoS None
DSCP 32, 34–38
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 1 CoS None
DSCP 48–63
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
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Feature (continued) Default Value
Standard receive queue 7 (intermediate priority)
Strict-priority transmit queue CoS 5
PFC QoS Default Configuration
Threshold 1 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 2 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 3 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
Threshold 4 CoS None
DSCP None
Tail-drop Enabled; 100%
WRED-drop Disabled; 100% low, 100% high
DSCP 40 and 46
Tail-drop 100% (nonconfigurable)
1p7q8t Transmit Queues
Feature Default Value
Standard transmit queue 1 (lowest priority)
Threshold 1 CoS 0
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 1
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 3–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
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PFC QoS Default Configuration
Feature (continued) Default Value
Standard transmit queue 2 (intermediate priority)
Standard transmit queue 3 (intermediate priority)
Standard transmit queues 4–7 (intermediate priorities)
Strict-priority transmit queue CoS 5
Chapter 42 Configuring PFC QoS
Threshold 1 CoS 2
Tail-drop Disabled; 70%
WRED-drop Enabled; 40% low, 70% high
Threshold 2 CoS 3 and 4
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 3–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Threshold 1 CoS 6 and 7
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Thresholds 2–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 100% low, 100% high
Thresholds 1–8 CoS None
Tail-drop Disabled; 100%
WRED-drop Enabled; 100% low, 100% high
Tail-drop 100% (nonconfigurable)
1p3q1t Transmit Queues
Feature Default Value
Standard transmit queue 1 (lowest priority)
Threshold 1 CoS 0 and 1
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Standard transmit queue 2 (medium priority)
Threshold 1 CoS 2, 3, and 4
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Standard transmit queue 3 (high priority)
Threshold 1 CoS 6 and 7
Tail-drop Disabled; 100%
WRED-drop Enabled; 70% low, 100% high
Strict-priority transmit queue CoS 5
Tail-drop 100% (nonconfigurable)
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1p2q1t Transmit Queues
Feature Default Value
Standard transmit queue 1 (lowest priority)
Standard transmit queue 3 (high priority)
Strict-priority transmit queue CoS 5
Threshold 1 CoS 0, 1, 2, and 3
Threshold 1 CoS 4, 6, and 7

Default Values With PFC QoS Disabled

PFC QoS Configuration Guidelines and Restrictions

Tail-drop Not supported
WRED-drop Enabled; 70% low, 100% high
Tail-drop Not supported
WRED-drop Enabled; 70% low, 100% high
Tail-drop 100% (nonconfigurable)
Feature Default Value
Ingress LAN port trust state trust DSCP.
Receive-queue drop-threshold percentages All thresholds set to 100%.
Transmit-queue drop-threshold percentages All thresholds set to 100%.
Transmit-queue bandwidth allocation ratio 255:1.
Transmit-queue size ratio Low priority: 100% (other queues not used).
CoS value and drop threshold mapping All QoS labels mapped to the low-priority queue.
PFC QoS Configuration Guidelines and Restrictions
When configuring PFC QoS, follow these guidelines and restrictions:
General Guidelines, page 42-50
PFC3 Guidelines, page 42-51
PFC2 Guidelines, page 42-52
Class Map Command Restrictions, page 42-53
Policy Map Command Restrictions, page 42-53
Policy Map Class Command Restrictions, page 42-53
Supported Granularity for CIR and PIR Rate Values, page 42-53
Supported Granularity for CIR and PIR Token Bucket Sizes, page 42-54
IP Precedence and DSCP Values, page 42-55
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PFC QoS Configuration Guidelines and Restrictions

General Guidelines

The match ip precedence and match ip dscp commands filter only IPv4 traffic.
In Release 12.2(18)SXE and later releases, the match precedence and match dscp commands filter
IPv4 and IPv6 traffic.
In Release 12.2(18)SXE and later releases, the set ip dscp and set ip precedence commands are
saved in the configuration file as set dscp and set precedence commands.
In Release 12.2(18)SXE and later releases, PFC QoS supports the set dscp and set precedence
policy map class commands for IPv4 and IPv6 traffic.
The flowmask requirements of QoS, NetFlow, and NetFlow data export (NDE) might conflict,
especially if you configure microflow policing.
With egress ACL support for remarked DSCP and VACL capture both configured on an interface,
VACL capture might capture two copies of each packet, and the second copy might be corrupt.
You cannot configure egress ACL support for remarked DSCP on tunnel interfaces.
Egress ACL support for remarked DSCP supports IP unicast traffic.
Egress ACL support for remarked DSCP is not relevant to multicast traffic. PFC QoS applies ingress
QoS changes to multicast traffic before applying egress QoS.
NetFlow and NetFlow data export (NDE) do not support interfaces where egress ACL support for
remarked DSCP is configured.
Chapter 42 Configuring PFC QoS
When egress ACL support for remarked DSCP is configured on any interface, you must configure
an interface-specific flowmask to enable NetFlow and NDE support on interfaces where egress ACL support for remarked DSCP is not configured. Enter either the mls flow ip interface-destination-source or the mls flow ip interface-full global configuration mode command.
Interface counters are not accurate on interfaces where egress ACL support for remarked DSCP is
configured.
You cannot apply microflow policing to IPv6 multicast traffic.
You cannot apply microflow policing to traffic that has been permitted by egress ACL support for
remarked DSCP.
Traffic that has been permitted by egress ACL support for remarked DSCP cannot be tagged as
MPLS traffic. (The traffic can be tagged as MPLS traffic on another network device.)
When you apply both ingress policing and egress policing to the same traffic, both the input policy
and the output policy must either mark down traffic or drop traffic. PFC QoS does not support ingress markdown with egress drop or ingress drop with egress markdown. (CSCea23571)
If traffic is both aggregate and microflow policed, then the aggregate and microflow policers must
both be in the same policy-map class and each must use the same conform-action and exceed-action keyword option: drop, set-dscp-transmit, set-prec-transmit, or transmit.
You cannot configure PFC QoS features on tunnel interfaces.
PFC QoS does not rewrite the payload ToS byte in tunnel traffic.
PFC QoS filters only by ACLs, dscp values, or IP precedence values.
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For these commands, PFC QoS applies identical configuration to all LAN ports controlled by the
same application-specific integrated circuit (ASIC):
Configure these commands only on physical ports. Do not configure these commands on logical
interfaces:
PFC QoS Configuration Guidelines and Restrictions
rcv-queue random-detect
rcv-queue queue-limit
wrr-queue queue-limit
wrr-queue bandwidth (except Gigabit Ethernet LAN ports)
priority-queue cos-map
rcv-queue cos-map
wrr-queue cos-map
wrr-queue threshold
rcv-queue threshold
wrr-queue random-detect
wrr-queue random-detect min-threshold
wrr-queue random-detect max-threshold
priority-queue cos-map
wrr-queue cos-map
wrr-queue random-detect
wrr-queue random-detect max-threshold
wrr-queue random-detect min-threshold
wrr-queue threshold
wrr-queue queue-limit
wrr-queue bandwidth
rcv-queue cos-map
rcv-queue bandwidth
rcv-queue random-detect
rcv-queue random-detect max-threshold
rcv-queue random-detect min-threshold
rcv-queue queue-limit
rcv-queue cos-map
rcv-queue threshold

PFC3 Guidelines

With Release 12.2(18)SXE and later releases, all versions of the PFC3 support QoS for IPv6 unicast
To display information about IPv6 PFC QoS, enter the show mls qos ipv6 command.
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PFC QoS Configuration Guidelines and Restrictions
The QoS features implemented in the port ASICs (queue architecture and dequeuing algorithms)
support IPv4 and IPv6 traffic.
The PFC3 supports IPv6 named extended ACLs and named standard ACLs.
In Release 12.2(18)SXE and later releases, the PFC3 supports the match protocol ipv6 command.
Because of conflicting TCAM lookup flow key bit requirements, you cannot configure IPv6
DSCP-based filtering and IPv6 Layer 4 range-based filtering on the same interface. For example:
If you configure both a DSCP value and a Layer 4 “greater than” (gt) or “less than” (lt) operator in an IPv6 ACE, you cannot use the ACL for PFC QoS filtering.
If you configure a DSCP value in one IPv6 ACL and a Layer 4 “greater than” (gt) or “less than” (lt) operator in another IPv6 ACL, you cannot use both ACLs in different class maps on the same interface for PFC QoS filtering.
In Release 12.2(18)SXE and later releases, you can apply aggregate and microflow policers to IPv6
traffic, but you cannot apply microflow policing to IPv6 multicast traffic.
With egress ACL support for remarked DSCP configured, the PFC3 does not provide
hardware-assistance for these features:
Cisco IOS reflexive ACLs
TCP intercept
Context-Based Access Control (CBAC)
Chapter 42 Configuring PFC QoS
With a PFC3, you cannot apply microflow policing to ARP traffic.
The PFC3 does not apply egress policing to traffic that is being bridged to the MSFC3.
The PFC3 does not apply egress policing or egress DSCP mutation to multicast traffic from the
With a PFC3, PFC QoS does not rewrite the ToS byte in bridged multicast traffic.

PFC2 Guidelines

The PFC2 supports the match protocol class map command, which configures NBAR and sends all
The PFC2 does not support these PFC QoS features:
The PFC2 does not support the modules that support ingress CoS mutation on IEEE 802.1Q tunnel
Network Address Translation (NAT)
MSFC3.
traffic on the Layer 3 interface, both ingress and egress, to be processed in software on the MSFC2. To configure NBAR, refer to this publication:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t8/dtnbarad.htm
Egress policing
Egress DSCP mutation
DSCP Transparency
VLAN-based QoS with DFCs installed
ports.
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Class Map Command Restrictions

With Release 12.2(18)SXE and later releases, PFC QoS supports the match any class map
command.
PFC QoS supports class maps that contain a single match command.
PFC QoS does not support these class map commands:
match cos
match any
match classmap
match destination-address
match input-interface
match qos-group
match source-address

Policy Map Command Restrictions

PFC QoS Configuration Guidelines and Restrictions
PFC QoS does not support these policy map commands:
class class_name destination-address
class class_name input-interface
class class_name protocol
class class_name qos-group
class class_name source-address

Policy Map Class Command Restrictions

PFC QoS does not support these policy map class commands:
bandwidth
priority
queue-limit
random-detect
set qos-group
service-policy

Supported Granularity for CIR and PIR Rate Values

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PFC QoS has the following hardware granularity for CIR and PIR rate values:
CIR and PIR Rate Value Range Granularity
32768 to 2097152 (2 Mbs) 32768 (32 Kb)
2097153 to 4194304 (4 Mbs) 65536 (64 Kb)
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CIR and PIR Rate Value Range Granularity
4194305 to 8388608 (8 Mbs) 131072 (128 Kb)
8388609 to 16777216 (16 Mbs) 262144 (256 Kb)
16777217 to 33554432 (32 Mbs) 524288 (512 Kb)
33554433 to 67108864 (64 Mbs) 1048576 (1 Mb)
67108865 to 134217728 (128 Mbs) 2097152 (2 Mb)
134217729 to 268435456 (256 Mbs) 4194304 (4 Mb)
268435457 to 536870912 (512 Mbs) 8388608 (8 Mb)
536870913 to 1073741824 (1 Gps) 16777216 (16 Mb)
1073741825 to 2147483648 (2 Gps) 33554432 (32 Mb)
2147483649 to 4294967296 (4 Gps) 67108864 (64 Mb)
4294967296 to 8589934592 (8 Gps) 134217728 (128 Mb)
8589934592 to 10000000000 (10 Gps) 268435456 (256 Mb)
Chapter 42 Configuring PFC QoS
Within each range, PFC QoS programs the PFC with rate values that are multiples of the granularity values.

Supported Granularity for CIR and PIR Token Bucket Sizes

PFC QoS has the following hardware granularity for CIR and PIR token bucket (burst) sizes:
CIR and PIR Token Bucket Size Range Granularity
1 to 32768 (32 KB) 1024 (1 KB)
32769 to 65536 (64 KB) 2048 (2 KB)
65537 to 131072 (128 KB) 4096 (4 KB)
131073 to 262144 (256 KB) 8196 (8 KB)
262145 to 524288 (512 KB) 16392 (16 KB)
524289 to 1048576 (1 MB) 32768 (32 KB)
1048577 to 2097152 (2 MB) 65536 (64 KB)
2097153 to 4194304 (4 MB) 131072 (128 KB)
4194305 to 8388608 (8 MB) 262144 (256 KB)
8388609 to 16777216 (16 MB) 524288 (512 KB)
16777217 to 33554432 (32 MB) 1048576 (1 MB)
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Within each range, PFC QoS programs the PFC with token bucket sizes that are multiples of the granularity values.
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IP Precedence and DSCP Values

Configuring PFC QoS

3-bit IP Precedence
00
10
20
30
1. MSb = most significant bit
6 MSb1 of ToS
876 543 876 543
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
1
0
0
0
0
1
0
0
0
1
1
0
0
0
1
1
0
0
0
0
0
1
0
0
0
1
0
0
1
0
1
0
0
1
0
1
0
0
0
1
1
0
0
0
1
1
0
0
1
1
1
0
0
1
1
1
0
0
0
0
0
1
0
0
0
1
0
1
0
0
1
0
1
0
0
1
0
0
1
0
1
0
0
1
0
1
0
1
1
0
1
0
1
1
0
1
0
0
1
1 1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
0
1
0
0
1
1
0
1
1
1
1
0
1
0
1
1
1
1
1
1
1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
6-bit DSCP
0 1 2 3 4 5 6 7
8
9 10 11 12 13 14 15
16 17 18 19 20 21 22 23
24 25 26 27 28 29 30 31
3-bit IP Precedence
41
51
61
71
6 MSb1 of ToS 6-bit
0
0
0
0
0
0
0
0
1
1
0
0
0
1
1
0
0
0
1
0
1
0
0
1
0
1
0
0
1
1
1
0
0
1
1
1
0
0
1
0
0
1
0
0
0
1
0
1
1
0
1
0
1
1
0
1
0
1
0
1
1
0
1
0
1
1
0
1
1
1
1
0
1
1
1
1
0
1
0
0
0
1
0
0
0
1
1
1
0
0
1
1
1
0
0
1
1
0
1
0
1
1
0
1
0
1
1
1
1
0
1
1
1
1
0
1
1
0
0
1
1
0
0
1
1
1
1
0
1
1
1
1
0
1
1
1
0
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1
DSCP
32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47
48 49 50 51 52 53 54 55
56 57 58 59 60 61 62 63
Configuring PFC QoS
These sections describe how to configure PFC QoS on the Cisco 7600 series routers:
Enabling PFC QoS Globally, page 42-56
Enabling Ignore Port Trust, page 42-57
Configuring DSCP Transparency, page 42-58
Enabling Queueing-Only Mode, page 42-58
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Enabling Microflow Policing of Bridged Traffic, page 42-59
Enabling VLAN-Based PFC QoS on Layer 2 LAN Ports, page 42-60
Enabling Egress ACL Support for Remarked DSCP, page 42-61
Creating Named Aggregate Policers, page 42-61
Configuring a PFC QoS Policy, page 42-64
Configuring Egress DSCP Mutation on a PFC3, page 42-82
Configuring Ingress CoS Mutation on IEEE 802.1Q Tunnel Ports, page 42-83
Configuring DSCP Value Maps, page 42-86
Configuring the Trust State of Ethernet LAN and OSM Ports, page 42-90
Configuring the Ingress LAN Port CoS Value, page 42-91
Configuring Standard-Queue Drop Threshold Percentages, page 42-92
Mapping QoS Labels to Queues and Drop Thresholds, page 42-98
Allocating Bandwidth Between Standard Transmit Queues, page 42-108
Setting the Receive-Queue Size Ratio, page 42-110
Configuring the Transmit-Queue Size Ratio, page 42-111
Note PFC QoS processes both unicast and multicast traffic.

Enabling PFC QoS Globally

To enable PFC QoS globally, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos
Router(config)# no mls qos
Router(config)# end
Router# show mls qos [ipv6]
This example shows how to enable PFC QoS globally:
Router# configure terminal Router(config)# mls qos Router(config)# end Router#
Enables PFC QoS globally on the router.
Disables PFC QoS globally on the router.
Exits configuration mode.
Verifies the configuration.
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This example shows how to verify the configuration:
Router# show mls qos QoS is enabled globally Microflow QoS is enabled globally
QoS global counters: Total packets: 544393 IP shortcut packets: 1410 Packets dropped by policing: 0 IP packets with TOS changed by policing: 467
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IP packets with COS changed by policing: 59998 Non-IP packets with COS changed by policing: 0
Router#

Enabling Ignore Port Trust

In Release 12.2(18)SXF5 and later releases, the ignore port trust feature allows an ingress policy to apply a configured IP precedence or DSCP value to any traffic, rather than only to untrusted traffic.
To enable ignore port trust, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos marking ignore port-trust
Router(config)# no mls qos marking ignore port-trust
Router(config)# end
Router# show mls qos | include ignores
Configuring PFC QoS
Enables ignore port trust globally on the router.
Disables ignore port trust globally on the router (default).
Exits configuration mode.
Verifies the configuration.
Note For untrusted traffic, when ignore port trust is enabled, PFC QoS does the following:
For IP traffic, PFC QoS uses the received DSCP value as the initial internal DSCP value.
For traffic without a recognizable ToS byte, PFC QoS maps the port CoS value to the initial internal
DSCP value.
This example shows how to enable ignore port trust and verify the configuration:
Router# configure terminal Router(config)# mls qos marking ignore port-trust Router(config)# end Router# show mls qos | include ignores
Policy marking ignores port_trust
Router#
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Configuring DSCP Transparency

Note In addition to support for other IP traffic, the PFC3B and PFC3BXL support the no mls qos rewrite
ip dscp command for MPLS traffic, traffic in IP in IP tunnels, and traffic in GRE tunnels.
The PFC3A supports the no mls qos rewrite ip dscp command for all IP traffic except MPLS traffic,
traffic in IP in IP tunnels, and traffic in GRE tunnels.
To enable DSCP transparency, which preserves the received Layer 3 ToS byte, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# no mls qos rewrite ip dscp
Router(config)# mls qos rewrite ip dscp
Router(config)# end
Router# show mls qos | include rewrite
Chapter 42 Configuring PFC QoS
Disables egress ToS-byte rewrite globally on the router.
Enables egress ToS-byte rewrite globally on the router.
Exits configuration mode.
Verifies the configuration.
When you preserve the received Layer 3 ToS byte, QoS uses the marked or marked-down CoS value for egress queueing and in egress tagged traffic.
This example shows how to preserve the received Layer 3 ToS byte and verify the configuration:
Router# configure terminal Router(config)# no mls qos rewrite ip dscp Router(config)# end Router# show mls qos | include rewrite
QoS ip packet dscp rewrite disabled globally
Router#

Enabling Queueing-Only Mode

To enable queueing-only mode on the router, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos queueing-only
Router(config)# no mls qos queueing-only
Router(config)# end
Router# show mls qos
Enables queueing-only mode on the router.
Disables PFC QoS globally on the router.
Note You cannot disable queueing-only mode
separately.
Exits configuration mode.
Verifies the configuration.
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When you enable queueing-only mode, the router does the following:
Disables marking and policing globally
Configures all ports to trust Layer 2 CoS
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Note The router applies the port CoS value to untagged ingress traffic and to traffic that is received
through ports that cannot be configured to trust CoS.
This example shows how to enable queueing-only mode:
Router# configure terminal Router(config)# mls qos queueing-only Router(config)# end Router#

Enabling Microflow Policing of Bridged Traffic

Note With a PFC2, to apply microflow policing to multicast traffic, you must enter the mls qos bridged
command on the Layer 3 multicast ingress interfaces.
By default, microflow policers affect only routed traffic. To enable microflow policing of bridged traffic on specified VLANs, perform this task:
Configuring PFC QoS
Step 1
Step 2
Step 3
Step 4
Command Purpose
Router(config)# interface {{vlan vlan_ID} |
1
{type
Router(config-if)# mls qos bridged
slot/port}}
Selects the interface to configure.
Enables microflow policing of bridged traffic, including bridge groups, on the VLAN.
Router(config-if)# no mls qos bridged
Router(config-if)# end
Router# show mls qos
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Disables microflow policing of bridged traffic.
Exits configuration mode.
Verifies the configuration.
This example shows how to enable microflow policing of bridged traffic on VLANs 3 through 5:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface range vlan 3 - 5 Router(config-if)# mls qos bridged Router(config-if)# end Router#
This example shows how to verify the configuration:
Router# show mls qos | begin Bridged QoS Bridged QoS is enabled on the following interfaces: Vl3 Vl4 Vl5 <...output truncated...> Router#
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Configuring PFC QoS

Enabling VLAN-Based PFC QoS on Layer 2 LAN Ports

Note With a PFC2, PFC QoS does not support VLAN-based QoS with DFCs installed.
With a PFC3, PFC QoS supports VLAN-based QoS with DFC3s installed.
With a PFC3, you can attach policy maps to Layer 3 interfaces for application of PFC QoS to egress
traffic. VLAN-based or port-based PFC QoS on Layer 2 ports is not relevant to application of PFC QoS to egress traffic on Layer 3 interfaces.
By default, PFC QoS uses policy maps attached to LAN ports. For ports configured as Layer 2 LAN ports with the switchport keyword, you can configure PFC QoS to use policy maps attached to a VLAN. Ports not configured with the switchport keyword are not associated with a VLAN.
To enable VLAN-based PFC QoS on a Layer 2 LAN port, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{type1slot/port} | {port-channel number}}
Router(config-if)# mls qos vlan-based
Selects the interface to configure.
Enables VLAN-based PFC QoS on a Layer 2 LAN port or a Layer 2 EtherChannel.
Router(config-if)# no mls qos vlan-based
Router(config-if)# end
Router# show mls qos
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Disables VLAN-based PFC QoS.
Exits configuration mode.
Verifies the configuration.
Chapter 42 Configuring PFC QoS
This example shows how to enable VLAN-based PFC QoS on Fast Ethernet port 5/42:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface fastethernet 5/42 Router(config-if)# mls qos vlan-based Router(config-if)# end
This example shows how to verify the configuration:
Router# show mls qos | begin QoS is vlan-based QoS is vlan-based on the following interfaces: Fa5/42 <...Output Truncated...>
Note Configuring a Layer 2 LAN port for VLAN-based PFC QoS preserves the policy map port configuration.
The no mls qos vlan-based port command reenables any previously configured port commands.
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Enabling Egress ACL Support for Remarked DSCP

To enable egress ACL support for remarked DSCP on an ingress interface, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{vlan vlan_ID} |
1
{type
Router(config-if)# platform ip features sequential [access-group IP_acl_name_or_number]
Router(config-if)# no platform ip features sequential [access-group IP_acl_name_or_number]
Router(config-if)# end
Router# show running-config interface ({type
slot/port} | {port-channel number}}
1
slot/port} | {port-channel number}}
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Selects the ingress interface to configure.
Enables egress ACL support for remarked DSCP on the ingress interface.
Disables egress ACL support for remarked DSCP on the ingress interface.
Exits configuration mode.
Verifies the configuration.
When configuring egress ACL support for remarked DSCP on an ingress interface, note the following information:
Configuring PFC QoS
To enable egress ACL support for remarked DSCP only for the traffic filtered by a specific standard,
extended named, or extended numbered IP ACL, enter the IP ACL name or number.
If you do not enter an IP ACL name or number, egress ACL support for remarked DSCP is enabled
for all IP ingress IP traffic on the interface.
This example shows how to enable egress ACL support for remarked DSCP on Fast Ethernet port 5/36:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface fastethernet 5/36 Router(config-if)# platform ip features sequential Router(config-if)# end

Creating Named Aggregate Policers

To create a named aggregate policer, perform this task:
Command Purpose
Router(config)# mls qos aggregate-policer policer_name bits_per_second normal_burst_bytes [maximum_burst_bytes] [pir peak_rate_bps] [[[conform-action {drop | set-dscp-transmit
dscp_value | set-prec-transmit transmit}] exceed-action {drop | policed-dscp | transmit}] violate-action {drop | policed-dscp | transmit}]
Router(config)# no mls qos aggregate-policer
policer_name
1. The set-dscp-transmit and set-prec-transmit keywords are only supported for IP traffic.
1
ip_precedence_value |
1
Creates a named aggregate policer.
Deletes a named aggregate policer.
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When creating a named aggregate policer, note the following information:
Aggregate policing works independently on each DFC-equipped switching module and
independently on the PFC, which supports any non-DFC-equipped switching modules. Aggregate policing does not combine flow statistics from different DFC-equipped switching modules. You can display aggregate policing statistics for each DFC-equipped switching module and for the PFC and any non-DFC-equipped switching modules supported by the PFC.
Each PFC or DFC polices independently, which might affect QoS features being applied to traffic
that is distributed across the PFC and any DFCs. Examples of these QoS feature are:
Policers applied to a port channel interface.
Policers applied to a switched virtual interface.
Egress policers applied to either a Layer 3 interface or an SVI. Note that PFC QoS performs egress policing decisions at the ingress interface, on the PFC or ingress DFC.
Policers affected by this restriction deliver an aggregate rate that is the sum of all the independent policing rates.
In Release 12.2(18)SXE and later releases, you can apply aggregate policers to IPv6 traffic.
With a PFC3, policing uses the Layer 2 frame size.
With a PFC2, policing uses the Layer 3 packet size.
See the “PFC QoS Configuration Guidelines and Restrictions” section on page 42-49 for
information about rate and burst size granularity.
The valid range of values for the CIR bits_per_second parameter is as follows:
Minimum—32 kilobits per second, entered as 32000
Maximum with Release 12.2(18)SXE and later releases: 10 gigabits per second, entered as 10000000000
Maximum with releases earlier than Release 12.2(18)SXE: 4 gigabits per second, entered as 4000000000
The normal_burst_bytes parameter sets the CIR token bucket size.
The maximum_burst_bytes parameter sets the PIR token bucket size.
When configuring the size of a token bucket, note the following information:
The minimum token bucket size is 1 kilobyte, entered as 1000 (the maximum_burst_bytes parameter must be set larger than the normal_burst_bytes parameter).
The maximum token bucket size is 32 megabytes, entered as 32000000.
To sustain a specific rate, set the token bucket size to be at least the rate value divided by 4000 because tokens are removed from the bucket every 1/4000th of a second (0.25 ms).
Because the token bucket must be large enough to hold at least one frame, set the parameter larger than the maximum size of the traffic being policed.
For TCP traffic, configure the token bucket size as a multiple of the TCP window size, with a minimum value at least twice as large as the maximum size of the traffic being policed.
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The valid range of values for the pir bits_per_second parameter is as follows:
(Optional) You can specify a conform action for matched in-profile traffic as follows:
Configuring PFC QoS
Minimum—32 kilobits per second, entered as 32000 (the value cannot be smaller than the CIR bits_per_second parameters)
Maximum with Release 12.2(18)SXE and later releases: 10 gigabits per second, entered as 10000000000
Maximum with releases earlier than Release 12.2(18)SXE: 4 gigabits per second, entered as 4000000000
The default conform action is transmit, which sets the policy map class trust state to trust DSCP unless the policy map class contains a trust command.
To set PFC QoS labels in untrusted traffic, enter the set-dscp-transmit keyword to mark matched untrusted traffic with a new DSCP value or enter the set-prec-transmit keyword to mark matched untrusted traffic with a new IP precedence value. The set-dscp-transmit and set-prec-transmit keywords are only supported for IP traffic. PFC QoS sets egress ToS and CoS from the configured value.
Enter the drop keyword to drop all matched traffic.
Note When you configure drop as the conform action, PFC QoS configures drop as the exceed
action and the violate action.
(Optional) For traffic that exceeds the CIR, you can specify an exceed action as follows:
The default exceed action is drop, except with a maximum_burst_bytes parameter (drop is not supported with a maximum_burst_bytes parameter).
Note When the exceed action is drop, PFC QoS ignores any configured violate action.
Enter the policed-dscp-transmit keyword to cause all matched out-of-profile traffic to be marked down as specified in the markdown map.
Note When you create a policer that does not use the pir keyword and the maximum_burst_bytes
parameter is equal to the normal_burst_bytes parameter (which is the case if you do not enter the maximum_burst_bytes parameter), the exceed-action policed-dscp-transmit keywords cause PFC QoS to mark traffic down as defined by the policed-dscp max-burst markdown map.
(Optional) For traffic that exceeds the PIR, you can specify a violate action as follows:
To mark traffic without policing, enter the transmit keyword to transmit all matched out-of-profile traffic.
The default violate action is equal to the exceed action.
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Enter the policed-dscp-transmit keyword to cause all matched out-of-profile traffic to be marked down as specified in the markdown map.
For marking without policing, enter the transmit keyword to transmit all matched out-of-profile traffic.
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Note When you apply both ingress policing and egress policing to the same traffic, both the input policy and
Chapter 42 Configuring PFC QoS
the output policy must either mark down traffic or drop traffic. PFC QoS does not support ingress markdown with egress drop or ingress drop with egress markdown.
This example shows how to create a named aggregate policer with a 1-Mbps rate limit and a 10-MB burst size that transmits conforming traffic and marks down out-of-profile traffic:
Router(config)# mls qos aggregate-policer aggr-1 1000000 10000000 conform-action transmit exceed-action policed-dscp-transmit
Router(config)# end Router#
This example shows how to verify the configuration:
Router# show mls qos aggregate-policer aggr-1 ag1 1000000 1000000 conform-action transmit exceed-action policed-dscp-transmit AgId=0 [pol4] Router#
The output displays the following:
The AgId parameter displays the hardware policer ID.
The policy maps that use the policer are listed in the square brackets ([]).

Configuring a PFC QoS Policy

These sections describe PFC QoS policy configuration:
PFC QoS Policy Configuration Overview, page 42-65
Configuring MAC ACLs, page 42-66
Configuring ARP ACLs for QoS Filtering, page 42-69
Configuring a Class Map, page 42-70
Verifying Class Map Configuration, page 42-72
Configuring a Policy Map, page 42-73
Verifying Policy Map Configuration, page 42-79
Attaching a Policy Map to an Interface, page 42-80
Note PFC QoS policies process both unicast and multicast traffic.
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PFC QoS Policy Configuration Overview

Note To mark traffic without limiting bandwidth utilization, create a policer that uses the transmit keywords
for both conforming and nonconforming traffic.
These commands configure traffic classes and the policies to be applied to those traffic classes and attach the policies to ports:
access-list (Optional for IP traffic. You can filter IP traffic with class-map commands.):
PFC QoS supports these ACL types:
Protocol Numbered ACLs Extended ACLs Named ACLs
IPv4 Yes:
IPv6 Yes (named) Yes
IPX (Supported only with PFC2)
MAC Layer No No Yes
ARP No No Yes
Configuring PFC QoS
1 to 99 1300 to 1999
Yes: 100 to 199 2000 to 2699
Yes
Yes: 800 to 899 Yes: 900 to 999 Yes
The PFC3 supports IPv6 named extended ACLs and named standard ACLs in Release
12.2(18)SXE and later releases.
The PFC3 supports ARP ACLs in Release 12.2(18)SXD and later releases.
Note —The PFC2 applies IP ACLs to ARP traffic.
—The PFC3 does not apply IP ACLs to ARP traffic.
—With a PFC3, you cannot apply microflow policing to ARP traffic.
The PFC3 does not support IPX ACLs. With the PFC3, you can configure MAC ACLs to filter IPX traffic.
With a PFC2, PFC QoS supports IPX ACLs that contain a source-network parameter and the optional destination-network and destination-node parameters. PFC QoS does not support IPX ACLs that contain other parameters (for example, source-node, protocol, source-socket, destination-socket, or service-type).
With a PFC2 or PFC3, PFC QoS supports time-based Cisco IOS ACLs.
Except for MAC ACLs and ARP ACLs, refer to the Cisco IOS Security Configuration Guide, Release 12.2, “Traffic Filtering and Firewalls,” at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fsecur_c/ftrafwl/in dex.htm
See Chapter 34, “Configuring Network Security,” for additional information about ACLs on the Cisco 7600 series routers.
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class-map (optional)—Enter the class-map command to define one or more traffic classes by
specifying the criteria by which traffic is classified.
policy-map—Enter the policy-map command to define the following:
service-policy—Enter the service-policy command to attach a policy map to an interface.

Configuring MAC ACLs

These sections describe MAC ACL configuration:
Configuring Protocol-Independent MAC ACL Filtering, page 42-66
Enabling VLAN-Based MAC QoS Filtering, page 42-67
Configuring MAC ACLs, page 42-68
Policy map class trust mode
Aggregate policing and marking
Microflow policing and marking
Chapter 42 Configuring PFC QoS
Note You can use MAC ACLs with VLAN ACLs (VACLs). For more information, see Chapter 36,
“Configuring VLAN ACLs.”
Configuring Protocol-Independent MAC ACL Filtering
With Release 12.2(18)SXD and later releases, PFC3BXL and PFC3B modes support protocol-independent MAC ACL filtering. Protocol-independent MAC ACL filtering applies MAC ACLs to all ingress traffic types (for example, IPv4 traffic, IPv6 traffic, and MPLS traffic, in addition to MAC-layer traffic).
You can configure these interface types for protocol-independent MAC ACL filtering:
VLAN interfaces without IP addresses
Physical LAN ports configured to support EoMPLS
Logical LAN subinterfaces configured to support EoMPLS
Ingress traffic permitted or denied by a MAC ACL on an interface configured for protocol-independent MAC ACL filtering is processed by egress interfaces as MAC-layer traffic. You cannot apply egress IP ACLs to traffic that was permitted or denied by a MAC ACL on an interface configured for protocol-independent MAC ACL filtering.
To configure protocol-independent MAC ACL filtering, perform this task:
Command Purpose
Step 1
Step 2
Router(config)# interface {{vlan vlan_ID} |
1
{type {port-channel number[.subinterface]}}
Router(config-if)# mac packet-classify
Router(config-if)# no mac packet-classify
slot/port[.subinterface]} |
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Selects the interface to configure.
Enables protocol-independent MAC ACL filtering on the interface.
Disables protocol-independent MAC ACL filtering on the interface.
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When configuring protocol-independent MAC ACL filtering, note the following information:
Do not configure protocol-independent MAC ACL filtering on VLAN interfaces where you have
configured an IP address.
Do not configure protocol-independent MAC ACL filtering with microflow policing when the
permitted traffic would be bridged or Layer 3 switched in hardware by the PFC3BXL.
Protocol-independent MAC ACL filtering supports microflow policing when the permitted traffic is
routed in software by the MSFC3.
This example shows how to configure VLAN interface 4018 for protocol-independent MAC ACL filtering and how to verify the configuration:
Router(config)# interface vlan 4018 Router(config-if)# mac packet-classify Router(config-if)# end Router# show running-config interface vlan 4018 | begin 4018 interface Vlan4018 mtu 9216 ipv6 enable mac packet-classify end
Configuring PFC QoS
This example shows how to configure Gigabit Ethernet interface 6/1 for protocol-independent MAC ACL filtering and how to verify the configuration:
Router(config)# interface gigabitethernet 6/1 Router(config-if)# mac packet-classify Router(config-if)# end Router# show running-config interface gigabitethernet 6/1 | begin 6/1 interface GigabitEthernet6/1 mtu 9216 no ip address mac packet-classify mpls l2transport route 4.4.4.4 4094 end
This example shows how to configure Gigabit Ethernet interface 3/24, subinterface 4000, for protocol-independent MAC ACL filtering and how to verify the configuration:
Router(config)# interface gigabitethernet 3/24.4000 Router(config-if)# mac packet-classify Router(config-if)# end Router# show running-config interface gigabitethernet 3/24.4000 | begin 3/24.4000 interface GigabitEthernet3/24.4000 encapsulation dot1Q 4000 mac packet-classify mpls l2transport route 4.4.4.4 4000 end
Enabling VLAN-Based MAC QoS Filtering
In Release 12.2(18)SXD and later releases in PFC3BXL or PFC3B mode, you can globally enable or disable VLAN-based QoS filtering in MAC ACLs. VLAN-based QoS filtering in MAC ACLs is disabled by default.
To enable VLAN-based QoS filtering in MAC ACLs, perform this task:
Command Purpose
Router(config)# mac packet-classify use vlan
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To disable VLAN-based QoS filtering in MAC ACLs, perform this task:
Command Purpose
Router(config)# no mac packet-classify use vlan
Disables VLAN-based QoS filtering in MAC ACLs.
Configuring MAC ACLs
You can configure named ACLs that filter IPX, DECnet, AppleTalk, VINES, or XNS traffic based on MAC addresses (IPX filtering with a MAC ACL is supported only with a PFC3).
In Release 12.2(17b)SXA and later releases in PFC3BXL or PFC3B mode, you can configure MAC ACLs that do VLAN-based filtering or CoS-based filtering or both.
In Release 12.2(18)SXD and later releases, you can globally enable or disable VLAN-based QoS filtering in MAC ACLs (disabled by default).
To configure a MAC ACL, perform this task:
Command Purpose
Step 1
Step 2
Router(config)# mac access-list extended list_name
Router(config)# no mac access-list extended list_name
Router(config-ext-macl)# {permit | deny} {src_mac_mask | any} {dest_mac_mask | any} [{protocol_keyword | {ethertype_number ethertype_mask}} [vlan vlan_ID] [cos cos_value]]
Router(config-ext-macl)# no {permit | deny} {src_mac_mask | any} {dest_mac_mask | any} [{protocol_keyword | {ethertype_number ethertype_mask}} [vlan vlan_ID] [cos cos_value]]
Configures a MAC ACL.
Deletes a MAC ACL.
Configures an access control entry (ACE) in a MAC ACL.
Deletes an ACE from a MAC ACL.
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When configuring an entry in a MAC-Layer ACL, note the following information:
The PFC3 supports the ipx-arpa and ipx-non-arpa keywords.
The PFC2 does not support the ipx-arpa and ipx-non-arpa keywords.
The vlan and cos keywords are supported in PFC3BXL or PFC3B mode with
Release 12.2(17b)SXA and later releases.
The vlan and cos keywords are not supported in MAC ACLs used for VACL filtering.
With Release 12.2(18)SXD and later releases, the vlan keyword for VLAN-based QoS filtering in
MAC ACLs can be globally enabled or disabled and is disabled by default.
You can enter MAC addresses as three 4-byte values in dotted hexadecimal format. For example,
0030.9629.9f84.
You can enter MAC address masks as three 4-byte values in dotted hexadecimal format. Use 1 bits
as wildcards. For example, to match an address exactly, use 0000.0000.0000 (can be entered as
0.0.0).
You can enter an EtherType and an EtherType mask as hexadecimal values.
Entries without a protocol parameter match any protocol.
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ACL entries are scanned in the order you enter them. The first matching entry is used. To improve
performance, place the most commonly used entries near the beginning of the ACL.
An implicit deny any any entry exists at the end of an ACL unless you include an explicit permit
any any entry at the end of the list.
All new entries to an existing list are placed at the end of the list. You cannot add entries to the
middle of a list.
This list shows the EtherType values and their corresponding protocol keywords:
Configuring PFC QoS
0x0600—xns-idp—Xerox XNS IDP
0x0BAD—vines-ip—Banyan VINES IP
0x0baf—vines-echo—Banyan VINES Echo
0x6000—etype-6000—DEC unassigned, experimental
0x6001—mop-dump—DEC Maintenance Operation Protocol (MOP) Dump/Load Assistance
0x6002—mop-console—DEC MOP Remote Console
0x6003—decnet-iv—DEC DECnet Phase IV Route
0x6004—lat—DEC Local Area Transport (LAT)
0x6005—diagnostic—DEC DECnet Diagnostics
0x6007—lavc-sca—DEC Local-Area VAX Cluster (LAVC), SCA
0x6008—amber—DEC AMBER
0x6009—mumps—DEC MUMPS
0x0800—ip—Malformed, invalid, or deliberately corrupt IP frames
0x8038—dec-spanning—DEC LANBridge Management
0x8039—dsm—DEC DSM/DDP
0x8040—netbios—DEC PATHWORKS DECnet NETBIOS Emulation
0x8041—msdos—DEC Local Area System Transport
0x8042—etype-8042—DEC unassigned
0x809B—appletalk—Kinetics EtherTalk (AppleTalk over Ethernet)
0x80F3—aarp—Kinetics AppleTalk Address Resolution Protocol (AARP)
This example shows how to create a MAC-Layer ACL named mac_layer that denies dec-phase-iv traffic with source address 0000.4700.0001 and destination address 0000.4700.0009, but permits all other traffic:
Router(config)# mac access-list extended mac_layer Router(config-ext-macl)# deny 0000.4700.0001 0.0.0 0000.4700.0009 0.0.0 dec-phase-iv Router(config-ext-macl)# permit any any

Configuring ARP ACLs for QoS Filtering

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Note The PFC2 applies IP ACLs to ARP traffic.
The PFC3 does not apply IP ACLs to ARP traffic.
With a PFC3, you cannot apply microflow policing to ARP traffic.
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Command Purpose
Step 1
Step 2
Router(config)# arp access-list list_name
Router(config)# no arp access-list list_name
Router(config-arp-nacl)# {permit | deny} {ip {any | host sender_ip | sender_ip sender_ip_wildcardmask} mac any
Router(config-arp-nacl)# no {permit | deny} {ip {any | host sender_ip | sender_ip sender_ip_wildcardmask} mac any
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With a PFC3 and Release 12.2(18)SXD and later releases, you can configure named ACLs that filter ARP traffic (EtherType 0x0806) for QoS.
To configure an ARP ACL for QoS filtering, perform this task:
Configures an ARP ACL for QoS filtering.
Deletes an ARP ACL.
Configures an access control entry (ACE) in an ARP ACL for QoS filtering.
Deletes an ACE from an ARP ACL.
When configuring an entry in an ARP ACL for QoS filtering, note the following information:
This publication describes the ARP ACL syntax that is supported in hardware by the PFC3. Any
other ARP ACL syntax displayed by the CLI help when you enter a question mark (“?”) is not supported and cannot be used to filter ARP traffic for QoS.
ACLs entries are scanned in the order you enter them. The first matching entry is used. To improve
performance, place the most commonly used entries near the beginning of the ACL.
An implicit deny ip any mac any entry exists at the end of an ACL unless you include an explicit
permit ip any mac any entry at the end of the list.
All new entries to an existing list are placed at the end of the list. You cannot add entries to the
middle of a list.
This example shows how to create an ARP ACL named arp_filtering that only permits ARP traffic from IP address 1.1.1.1:
Router(config)# arp access-list arp_filtering Router(config-arp-nacl)# permit ip host 1.1.1.1 mac any

Configuring a Class Map

These sections describe class map configuration:
Creating a Class Map, page 42-70
Class Map Filtering Guidelines and Restrictions, page 42-71
Configuring Filtering in a Class Map, page 42-71
Creating a Class Map
To create a class map, perform this task:
Command Purpose
Router(config)# class-map class_name
Router(config)# no class-map class_name
Creates a class map.
Deletes a class map.
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Class Map Filtering Guidelines and Restrictions
When configuring class map filtering, follow these guidelines and restrictions:
With Release 12.2(18)SXE and later releases, PFC QoS supports multiple match criteria in class
maps configured with the match-any keywords.
With releases earlier than Release 12.2(18)SXE, PFC QoS supports class maps that contain a single
match command.
With Release 12.2(18)SXE and later releases, the PFC3 supports the match protocol ipv6
command.
Because of conflicting TCAM lookup flow key bit requirements, you cannot configure IPv6
DSCP-based filtering and IPv6 Layer 4 range-based filtering on the same interface. For example:
If configure both a DSCP value and a Layer 4 greater than (gt) or less than (lt) operator in an IPv6 ACE, you cannot use the ACL for PFC QoS filtering.
If configure a DSCP value in one IPv6 ACL and a Layer 4 greater than (gt) or less than (lt) operator in another IPv6 ACL, you cannot use both ACLs in different class maps on the same interface for PFC QoS filtering.
Release 12.2(18)SXE and later releases support the match protocol ip command for IPv4 traffic.
PFC QoS does not support the match cos, match any, match classmap, match
destination-address, match input-interface, match qos-group, and match source-address class map commands.
Cisco 7600 series routers do not detect the use of unsupported commands until you attach a policy
map to an interface.
Configuring PFC QoS
The PFC2 support the match protocol class map command, which configures NBAR and sends all
traffic on the Layer 3 interface, both ingress and egress, to be processed in software on the MSFC2. To configure NBAR, refer to this publication:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t8/dtnbarad.htm
Filtering based on IP precedence or DSCP for egress QoS uses the received IP precedence or DSCP.
Egress QoS filtering is not based on any IP precedence or DSCP changes made by ingress QoS.
Note This chapter includes the following ACL documentation:
Configuring MAC ACLs, page 42-66
Configuring ARP ACLs for QoS Filtering, page 42-69
Other ACLs are not documented in this publication. See the references under access-list in the
“PFC QoS Policy Configuration Overview” section on page 42-65.
Configuring Filtering in a Class Map
To configure filtering in a class map, perform one of these tasks:
Command Purpose
Router(config-cmap)# match access-group name acl_index_or_name
Router(config-cmap)# no match access-group name acl_index_or_name
(Optional) Configures the class map to filter using an ACL.
Clears the ACL configuration from the class map.
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Command Purpose
Router (config-cmap)# match protocol ipv6
(Optional—for IPv6 traffic) Configures the class map to filter IPv6 traffic.
Router (config-cmap)# no match protocol ipv6
Router (config-cmap)# match precedence ipp_value1 [ipp_value2 [ipp_valueN]]
Router (config-cmap)# no match precedence ipp_value1 [ipp_value2 [ipp_valueN]]
Router (config-cmap)# match dscp dscp_value1 [dscp_value2 [dscp_valueN]]
Router (config-cmap)# no match dscp dscp_value1 [dscp_value2 [dscp_valueN]]
Router (config-cmap)# match ip precedence ipp_value1 [ipp_value2 [ipp_valueN]]
Router (config-cmap)# no match ip precedence ipp_value1 [ipp_value2 [ipp_valueN]]
Router (config-cmap)# match ip dscp dscp_value1 [dscp_value2 [dscp_valueN]]
Router (config-cmap)# no match ip dscp dscp_value1 [dscp_value2 [dscp_valueN]]
Clears IPv6 filtering.
(Optional—for IPv4 or IPv6 traffic) Configures the class map to filter based on up to eight IP precedence values.
Note Does not support source-based or destination-based
Clears configured IP precedence values from the class map.
(Optional—for IPv4 or IPv6 traffic only) Configures the class map to filter based on up to eight DSCP values.
Note Does not support source-based or destination-based
Clears configured DSCP values from the class map.
(Optional—for IPv4 traffic) Configures the class map to filter based on up to eight IP precedence values.
Note Does not support source-based or destination-based
Clears configured IP precedence values from the class map.
(Optional—for IPv4 traffic) Configures the class map to filter based on up to eight DSCP values.
Note Does not support source-based or destination-based
Clears configured DSCP values from the class map.
Chapter 42 Configuring PFC QoS
microflow policing.
microflow policing.
microflow policing.
microflow policing.

Verifying Class Map Configuration

To verify class map configuration, perform this task:
Command Purpose
Step 1
Step 2
Router (config-cmap)# end
Router# show class-map class_name
This example shows how to create a class map named ipp5 and how to configure filtering to match traffic with IP precedence 5:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# class-map ipp5 Router(config-cmap)# match ip precedence 5 Router(config-cmap)# end
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Exits configuration mode.
Verifies the configuration.
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This example shows how to verify the configuration:
Router# show class-map ipp5 Class Map match-all ipp5 (id 1) Match ip precedence 5

Configuring a Policy Map

You can attach only one policy map to an interface. Policy maps can contain one or more policy map classes, each with different policy map commands.
Configure a separate policy map class in the policy map for each type of traffic that an interface receives. Put all commands for each type of traffic in the same policy map class. PFC QoS does not attempt to apply commands from more than one policy map class to matched traffic.
These sections describe policy map configuration:
Creating a Policy Map, page 42-73
Policy Map Class Configuration Guidelines and Restrictions, page 42-73
Creating a Policy Map Class and Configuring Filtering, page 42-74
Configuring Policy Map Class Actions, page 42-74
Configuring PFC QoS
Creating a Policy Map
To create a policy map, perform this task:
Command Purpose
Router(config)# policy-map policy_name
Router(config)# no policy-map policy_name
Creates a policy map.
Deletes the policy map.
Policy Map Class Configuration Guidelines and Restrictions
When you configuring policy map classes, follow the guidelines and restrictions:
The PFC2 support the class class_name protocol policy map command, which configures NBAR
and sends all traffic on the Layer 3 interface, both ingress and egress, to be processed in software on the MSFC2. To configure NBAR, refer to this publication:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t8/dtnbarad.htm
PFC QoS does not support the class class_name destination-address, class class_name
input-interface, class class_name qos-group, and class class_name source-address policy map
commands.
With Release 12.2(18)SXE and later releases, PFC QoS supports the class default policy map
command.
PFC QoS does not detect the use of unsupported commands until you attach a policy map to an
interface.
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Creating a Policy Map Class and Configuring Filtering
To create a policy map class and configure it to filter with a class map, perform this task:
Command Purpose
Router(config-pmap)# class class_name
Creates a policy map class and configures it to filter with a class map.
Note PFC QoS supports class maps that contain a single
Router(config-pmap)# no class class_name
Clears use of the class map.
Configuring Policy Map Class Actions
When configuring policy map class actions, note the following information:
Policy maps can contain one or more policy map classes.
Put all trust-state and policing commands for each type of traffic in the same policy map class.
PFC QoS only applies commands from one policy map class to traffic. After traffic has matched the
filtering in one policy map class, QoS does apply the filtering configured in other policy map classes.
For hardware-switched traffic, PFC QoS does not support the bandwidth, priority, queue-limit, or
random-detect policy map class commands. You can configure these commands because they can
be used for software-switched traffic.
Chapter 42 Configuring PFC QoS
match command.
PFC QoS does not support the set qos-group policy map class commands.
PFC QoS supports the set ip dscp and set ip precedence policy map class commands for IPv4
traffic.
In Release 12.2(18)SXD and later releases and in Release 12.2(17d)SXB and later releases, you can use the set ip dscp and set ip precedence commands on non-IP traffic to mark the internal DSCP value, which is the basis of the egress Layer 2 CoS value.
In Release 12.2(18)SXE and later releases, the set ip dscp and set ip precedence commands are saved in the configuration file as set dscp and set precedence commands.
In Release 12.2(18)SXE and later releases, PFC QoS supports the set dscp and set precedence
policy map class commands for IPv4 and IPv6 traffic.
You cannot do all three of the following in a policy map class:
Mark traffic with the set commands
Configure the trust state
Configure policing
In a policy map class, you can either mark traffic with the set commands or do one or both of the following:
Configure the trust state
Configure policing
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Note When configure policing, you can mark traffic with policing keywords.
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These sections describe policy map class action configuration:
Configuring Policy Map Class Marking, page 42-75
Configuring the Policy Map Class Trust State, page 42-75
Configuring Policy Map Class Policing, page 42-76
Configuring Policy Map Class Marking
In Release 12.2(18)SXF5 and later releases, when the ignore port trust feature is enabled, PFC QoS supports policy map class marking for all traffic with set policy map class commands.
In all releases, PFC QoS supports policy map class marking for untrusted traffic with set policy map class commands.
To configure policy map class marking, perform this task:
Command Purpose
Router(config-pmap-c)# set {dscp dscp_value | precedence ip_precedence_value}
Router(config-pmap-c)# no set {dscp dscp_value | precedence ip_precedence_value}
Configures the policy map class to mark matched untrusted traffic with the configured DSCP or IP precedence value.
Clears the marking configuration.
Configuring PFC QoS
Note Releases earlier than Release 12.2(18)SXE support the set ip dscp and set ip precedence policy map
class commands.
Configuring the Policy Map Class Trust State
Note You cannot attach a policy map that configures a trust state with the service-policy output command.
To configure the policy map class trust state, perform this task:
Command Purpose
Router(config-pmap-c)# trust {cos | dscp | ip-precedence}
Configures the policy map class trust state, which selects the value that PFC QoS uses as the source of the initial internal DSCP value.
Router(config-pmap-c)# no trust
Reverts to the default policy-map class trust state (untrusted).
When configuring the policy map class trust state, note the following information:
Enter the no trust command to use the trust state configured on the ingress port (this is the default).
With the cos keyword, PFC QoS sets the internal DSCP value from received or ingress port CoS.
With the dscp keyword, PFC QoS uses received DSCP.
With the ip-precedence keyword, PFC QoS sets DSCP from received IP precedence.
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Note Policing with the conform-action transmit keywords sets the port trust state of matched traffic to trust
Chapter 42 Configuring PFC QoS
Configuring Policy Map Class Policing
When you configure policy map class policing, note the following information:
PFC QoS does not support the set-qos-transmit policer keyword.
PFC QoS does not support the set-dscp-transmit or set-prec-transmit keywords as arguments to
the exceed-action keyword.
PFC QoS does not detect the use of unsupported keywords until you attach a policy map to an
interface.
These sections describe configuration of policy map class policing:
Using a Named Aggregate Policer, page 42-76
Configuring a Per-Interface Policer, page 42-76
DSCP or to the trust state configured by a trust command in the policy map class.
Using a Named Aggregate Policer
To use a named aggregate policer, perform this task:
Command Purpose
Router(config-pmap-c)# police aggregate aggregate_name
Router(config-pmap-c)# no police aggregate aggregate_name
Configures the policy map class to use a previously defined named aggregate policer.
Clears use of the named aggregate policer.
Configuring a Per-Interface Policer
To configure a per-interface policer, perform this task:
Command Purpose
Router(config-pmap-c)# police [flow [mask { src-only | dest-only | full-flow}]] bits_per_second
normal_burst_bytes [maximum_burst_bytes] [pir peak_rate_bps] [[[conform-action {drop | set-dscp-transmit dscp_value | set-prec-transmit ip_precedence_value | transmit}] exceed-action {drop
| policed-dscp | transmit}] violate-action {drop | policed-dscp | transmit}]
Router(config-pmap-c)# no police [flow [mask {src-only | dest-only | full-flow}]] bits_per_second
normal_burst_bytes [maximum_burst_bytes] [pir peak_rate_bps] [[[conform-action {drop | set-dscp-transmit dscp_value | set-prec-transmit ip_precedence_value | transmit}] exceed-action {drop
| policed-dscp | transmit}] violate-action {drop | policed-dscp | transmit}]
Creates a per-interface policer and configures the policy-map class to use it.
Deletes the per-interface policer from the policy-map class.
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When configuring a per-interface policer, note the following information:
Aggregate policing works independently on each DFC-equipped switching module and
independently on the PFC, which supports any non-DFC-equipped switching modules. Aggregate policing does not combine flow statistics from different DFC-equipped switching modules. You can display aggregate policing statistics for each DFC-equipped switching module and for the PFC and any non-DFC-equipped switching modules supported by the PFC.
Each PFC or DFC polices independently, which might affect QoS features being applied to traffic
that is distributed across the PFC and any DFCs. Examples of these QoS feature are:
Policers affected by this restriction deliver an aggregate rate that is the sum of all the independent policing rates.
With a PFC3, when you apply both ingress policing and egress policing to the same traffic, both the
input policy and the output policy must either mark down traffic or drop traffic. PFC QoS does not support ingress markdown with egress drop or ingress drop with egress markdown.
Configuring PFC QoS
Policers applied to a port channel interface.
Policers applied to a switched virtual interface.
Egress policers applied to either a Layer 3 interface or an SVI. Note that PFC QoS performs egress policing decisions at the ingress interface, on the PFC or ingress DFC.
With Release 12.2(18)SXE and later releases, you can apply aggregate and microflow policers to
IPv6 traffic.
With a PFC3, policing uses the Layer 2 frame size.
With a PFC2, policing uses the Layer 3 packet size.
See the “PFC QoS Configuration Guidelines and Restrictions” section on page 42-49 for
information about rate and burst size granularity.
You can enter the flow keyword to define a microflow policer (you cannot apply microflow policing
to ARP traffic). When configuring a microflow policer, note the following information:
With a PFC3, you can enter the mask src-only keywords to base flow identification only on source addresses, which applies the microflow policer to all traffic from each source address. Release 12.2(17d)SXB and later releases support the mask src-only keywords for both IP traffic and MAC traffic. Releases earlier than Release 12.2(17d)SXB support the mask src-only keywords only for IP traffic.
With a PFC3, you can enter the mask dest-only keywords to base flow identification only on destination addresses, which applies the microflow policer to all traffic to each source address. Release 12.2(17d)SXB and later releases support the mask dest-only keywords for both IP traffic and MAC traffic. Releases earlier than Release 12.2(17d)SXB support the mask dest-only keywords only for IP traffic.
By default and with the mask full-flow keywords, PFC QoS bases IP flow identification on source IP address, destination IP address, the Layer 3 protocol, and Layer 4 port numbers.
With a PFC2, PFC QoS considers IPX traffic with same source network, destination network, and destination node to be part of the same flow, including traffic with different source nodes or sockets.
PFC QoS considers MAC-Layer traffic with the same protocol and the same source and destination MAC-Layer addresses to be part of the same flow, including traffic with different EtherTypes.
Microflow policers do not support the maximum_burst_bytes parameter, the pir bits_per_second keyword and parameter, or the violate-action keyword.
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Note The flowmask requirements of microflow policing, NetFlow, and NetFlow data export
(NDE) might conflict.
The valid range of values for the CIR bits_per_second parameter is as follows:
Minimum—32 kilobits per second, entered as 32000
Maximum with Release 12.2(18)SXE and later releases: 10 gigabits per second, entered as 10000000000
Maximum with releases earlier than Release 12.2(18)SXE: 4 gigabits per second, entered as 4000000000
The normal_burst_bytes parameter sets the CIR token bucket size.
The maximum_burst_bytes parameter sets the PIR token bucket size (not supported with the flow
keyword)
When configuring the size of a token bucket, note the following information:
The minimum token bucket size is 1 kilobyte, entered as 1000 (the maximum_burst_bytes parameter must be set larger than the normal_burst_bytes parameter)
The maximum token bucket size is 32 megabytes, entered as 32000000
To sustain a specific rate, set the token bucket size to be at least the rate value divided by 4000, because tokens are removed from the bucket every 1/4000th of a second (0.25 ms).
Because the token bucket must be large enough to hold at least one frame, set the parameter larger than the maximum size of the traffic being policed.
For TCP traffic, configure the token bucket size as a multiple of the TCP window size, with a minimum value at least twice as large as the maximum size of the traffic being policed.
(Not supported with the flow keyword.) The valid range of values for the pir bits_per_second
parameter is as follows:
Minimum—32 kilobits per second, entered as 32000 (the value cannot be smaller than the CIR bits_per_second parameters)
Maximum with Release 12.2(18)SXE and later releases: 10 gigabits per second, entered as 10000000000
Maximum with releases earlier than Release 12.2(18)SXE: 4 gigabits per second, entered as 4000000000
(Optional) You can specify a conform action for matched in-profile traffic as follows:
The default conform action is transmit, which sets the policy map class trust state to trust DSCP unless the policy map class contains a trust command.
To set PFC QoS labels in untrusted traffic, you can enter the set-dscp-transmit keyword to mark matched untrusted traffic with a new DSCP value or enter the set-prec-transmit keyword to mark matched untrusted traffic with a new IP precedence value. The set-dscp-transmit and set-prec-transmit keywords are only supported for IP traffic. PFC QoS sets egress ToS and CoS from the configured value.
You can enter the drop keyword to drop all matched traffic.
Ensure that aggregate and microflow policers that are applied to the same traffic each specify the same conform-action behavior.
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(Optional) For traffic that exceeds the CIR, you can specify an exceed action as follows:
Note When the exceed action is drop, PFC QoS ignores any configured violate action.
Note When you create a policer that does not use the pir keyword and the maximum_burst_bytes
Configuring PFC QoS
For marking without policing, you can enter the transmit keyword to transmit all matched out-of-profile traffic.
The default exceed action is drop, except with a maximum_burst_bytes parameter (drop is not supported with a maximum_burst_bytes parameter).
You can enter the policed-dscp-transmit keyword to cause all matched out-of-profile traffic to be marked down as specified in the markdown map.
parameter is equal to the normal_burst_bytes parameter (which is the case if you do not enter the maximum_burst_bytes parameter), the exceed-action policed-dscp-transmit keywords cause PFC QoS to mark traffic down as defined by the policed-dscp max-burst markdown map.
(Optional—Not supported with the flow keyword) for traffic that exceeds the PIR, you can specify
a violate action as follows:
For marking without policing, you can enter the transmit keyword to transmit all matched out-of-profile traffic.
The default violate action is equal to the exceed action.
You can enter the policed-dscp-transmit keyword to cause all matched out-of-profile traffic to be marked down as specified in the markdown map.
This example shows how to create a policy map named max-pol-ipp5 that uses the class-map named ipp5, which is configured to trust received IP precedence values and is configured with a maximum-capacity aggregate policer and with a microflow policer:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# policy-map max-pol-ipp5 Router(config-pmap)# class ipp5 Router(config-pmap-c)# trust ip-precedence Router(config-pmap-c)# police 2000000000 2000000 conform-action set-prec-transmit 6 exceed-action policed-dscp-transmit Router(config-pmap-c)# police flow 10000000 10000 conform-action set-prec-transmit 6 exceed-action policed-dscp-transmit Router(config-pmap-c)# end

Verifying Policy Map Configuration

To verify policy map configuration, perform this task:
Step 1
Step 2
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Router(config-pmap-c)# end
Router# show policy-map policy_name
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Exits policy map class configuration mode.
Note Enter additional class commands to create
Verifies the configuration.
additional classes in the policy map.
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This example shows how to verify the configuration:
Router# show policy-map max-pol-ipp5 Policy Map max-pol-ipp5 class ipp5
class ipp5 police flow 10000000 10000 conform-action set-prec-transmit 6 exceed-action policed-dscp-transmit trust precedence police 2000000000 2000000 2000000 conform-action set-prec-transmit 6 exceed-action policed-dscp-transmit
Router#

Attaching a Policy Map to an Interface

To attach a policy map to an interface, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{vlan vlan_ID} |
1
{type number[.subinterface]}}
Router(config-if)# service-policy [input | output] policy_map_name
Router(config-if)# no service-policy [input | output] policy_map_name
Router(config-if)# end
Router# show policy-map interface {{vlan vlan_ID} | {type
slot/port[.subinterface]} | {port-channel
1
slot/port} | {port-channel number}}
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Chapter 42 Configuring PFC QoS
Selects the interface to configure.
Attaches a policy map to the interface.
Removes the policy map from the interface.
Exits configuration mode.
Verifies the configuration.
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When attaching a policy map to an interface, note the following information:
Do not attach a service policy to a port that is a member of an EtherChannel.
With DFCs installed, PFC2 does not support VLAN-based QoS: you cannot enter the mls qos
vlan-based command or attach service policies to VLAN interfaces.
PFC QoS supports the output keyword only with a PFC3 and only on Layer 3 interfaces (either LAN
ports configured as Layer 3 interfaces or VLAN interfaces). With a PFC3, you can attach both an input and an output policy map to a Layer 3 interface.
VLAN-based or port-based PFC QoS on Layer 2 ports is not relevant to policies attached to Layer
3 interfaces with the output keyword.
Policies attached with the output keyword do not support microflow policing.
You cannot attach a policy map that configures a trust state with the service-policy output
command.
Filtering based on IP precedence or DSCP in policies attached with the output keyword uses the
received IP precedence or DSCP values. Filtering based on IP precedence or DSCP in policies attached with the output keyword is not based on any IP precedence or DSCP changes made by ingress QoS.
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Aggregate policing works independently on each DFC-equipped switching module and
independently on the PFC, which supports any non-DFC-equipped switching modules. Aggregate policing does not combine flow statistics from different DFC-equipped switching modules. You can display aggregate policing statistics for each DFC-equipped switching module and for the PFC and any non-DFC-equipped switching modules supported by the PFC.
Each PFC or DFC polices independently, which might affect QoS features being applied to traffic
that is distributed across the PFC and any DFCs. Examples of these QoS feature are:
Policers affected by this restriction deliver an aggregate rate that is the sum of all the independent policing rates.
With a PFC3, when you apply both ingress policing and egress policing to the same traffic, both the
input policy and the output policy must either mark down traffic or drop traffic. PFC QoS does not support ingress markdown with egress drop or ingress drop with egress markdown.
This example shows how to attach the policy map named pmap1 to Fast Ethernet port 5/36:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface fastethernet 5/36 Router(config-if)# service-policy input pmap1 Router(config-if)# end
Configuring PFC QoS
Policers applied to a port channel interface.
Policers applied to a switched virtual interface.
Egress policers applied to either a Layer 3 interface or an SVI. Note that PFC QoS performs egress policing decisions at the ingress interface, on the PFC or ingress DFC.
This example shows how to verify the configuration:
Router# show policy-map interface fastethernet 5/36 FastEthernet5/36 service-policy input: pmap1 class-map: cmap1 (match-all) 0 packets, 0 bytes 5 minute rate 0 bps match: ip precedence 5 class cmap1 police 8000 8000 conform-action transmit exceed-action drop class-map: cmap2 (match-any) 0 packets, 0 bytes 5 minute rate 0 bps match: ip precedence 2 0 packets, 0 bytes 5 minute rate 0 bps class cmap2 police 8000 10000 conform-action transmit exceed-action drop Router#
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Configuring Egress DSCP Mutation on a PFC3

Note The PFC2 does not support egress DSCP mutation.
These sections describe how to configure egress DSCP mutation on a PFC3:
Configuring Named DSCP Mutation Maps, page 42-82
Attaching an Egress DSCP Mutation Map to an Interface, page 42-83

Configuring Named DSCP Mutation Maps

To configure a named DSCP mutation map, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos map dscp-mutation map_name dscp1 [dscp2 [dscp3 [dscp4 [dscp5 [dscp6 [dscp7 [dscp8]]]]]]] to mutated_dscp
Router(config)# no mls qos map dscp-mutation map_name
Router(config)# end
Router# show mls qos maps
Configures a named DSCP mutation map.
Reverts to the default map.
Exits configuration mode.
Verifies the configuration.
Chapter 42 Configuring PFC QoS
When configuring a named DSCP mutation map, note the following information:
You can enter up to 8 DSCP values that map to a mutated DSCP value.
You can enter multiple commands to map additional DSCP values to a mutated DSCP value.
You can enter a separate command for each mutated DSCP value.
This example shows how to map DSCP 30 to mutated DSCP value 8:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map dscp-mutation mutmap1 30 to 8 Router(config)# end Router#
This example shows how to verify the configuration:
Router# show mls qos map | begin DSCP mutation DSCP mutation map mutmap1: (dscp= d1d2) d1 : d2 0 1 2 3 4 5 6 7 8 9
------------------------------------­ 0 : 00 01 02 03 04 05 06 07 08 09 1 : 10 11 12 13 14 15 16 17 18 19 2 : 20 21 22 23 24 25 26 27 28 29 3 : 08 31 32 33 34 35 36 37 38 39 4 : 40 41 42 43 44 45 46 47 48 49 5 : 50 51 52 53 54 55 56 57 58 59 6 : 60 61 62 63 <...Output Truncated...> Router#
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Note In the DSCP mutation map displays, the marked-down DSCP values are shown in the body of the matrix;
the first digit of the original DSCP value is in the column labeled d1 and the second digit is in the top row. In the example shown, DSCP 30 maps to DSCP 08.

Attaching an Egress DSCP Mutation Map to an Interface

To attach an egress DSCP mutation map to an interface, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{vlan vlan_ID} |
1
{type {port-channel number[.subinterface]}}
Router(config-if)# mls qos dscp-mutation mutation_map_name
Router(config-if)# no mls qos dscp-mutation mutation_map_name
Router(config-if)# end
Router# show running-config interface {{vlan
vlan_ID} | {type number}}
slot/port[.subinterface]} |
1
slot/port} | {port-channel
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Selects the interface to configure.
Attaches an egress DSCP mutation map to the interface.
Removes the egress DSCP mutation map from the interface.
Exits configuration mode.
Verifies the configuration.
Configuring PFC QoS
This example shows how to attach the egress DSCP mutation map named mutmap1 to Fast Ethernet port 5/36:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface fastethernet 5/36 Router(config-if)# mls qos dscp-mutation mutmap1 Router(config-if)# end

Configuring Ingress CoS Mutation on IEEE 802.1Q Tunnel Ports

Note The Supervisor Engine 2 does not support the switching modules that support ingress CoS mutation.
Release 12.2(17b)SXA and later releases support ingress CoS mutation on IEEE 802.1Q tunnel ports configured to trust received CoS (see the “Ingress CoS Mutation Configuration Guidelines and
Restrictions” section on page 42-84 for the list of supported modules).
When you configure ingress CoS mutation on an IEEE 802.1Q tunnel port that you have configured to trust received CoS, PFC QoS uses the mutated CoS value instead of the received CoS value in the ingress drop thresholds and for any trust CoS marking and policing.
These sections describe how to configure ingress CoS mutation:
Ingress CoS Mutation Configuration Guidelines and Restrictions, page 42-84
Configuring Ingress CoS Mutation Maps, page 42-85
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Ingress CoS Mutation Configuration Guidelines and Restrictions

When configuring ingress CoS mutation, follow these guidelines and restrictions:
Release 12.2(17b)SXA and later releases support ingress CoS mutation on WS-X6704-10GE,
WS-X6748-SFP, WS-X6724-SFP, and WS-X6748-GE-TX switching modules.
Ports that are not configured as IEEE 802.1Q tunnel ports do not support ingress CoS mutation.
Ports that are not configured to trust received CoS do not support ingress CoS mutation.
Ingress CoS mutation does not change the CoS value carried by the customer frames. When the
customer traffic exits the 802.1Q tunnel, the original CoS is intact.
Ingress CoS mutation configuration applies to all ports in a port group. The port groups are:
WS-X6704-10GE—4 ports, 4 port groups, 1 port in each group
WS-X6748-SFP—48 ports, 4 port groups: ports 1–12, 13–24, 25–36, and 37–48
WS-X6724-SFP—24 ports, 2 port groups: ports 1–12 and 13–24
WS-X6748-GE-TX—48 ports, 4 port groups: ports 1–12, 13–24, 25–36, and 37–48
To avoid ingress CoS mutation configuration failures, only create EtherChannels where all member
ports support ingress CoS mutation or where no member ports support ingress CoS mutation. Do not create EtherChannels with mixed support for ingress CoS mutation.
If you configure ingress CoS mutation on a port that is a member of an EtherChannel, the ingress
CoS mutation is applied to the port-channel interface.
You can configure ingress CoS mutation on port-channel interfaces.
Chapter 42 Configuring PFC QoS
With ingress CoS mutation configured on a port-channel interface, the following occurs:
The ingress CoS mutation configuration is applied to the port groups of all member ports of the EtherChannel. If any member port cannot support ingress CoS mutation, the configuration fails.
If a port in the port group is a member of a second EtherChannel, the ingress CoS mutation configuration is applied to the second port-channel interface and to the port groups of all member ports of the second EtherChannel. If any member port of the second EtherChannel cannot support ingress CoS mutation, the configuration fails on the first EtherChannel. If the configuration originated on a nonmember port in a port group that has a member port of the first EtherChannel, the configuration fails on the nonmember port.
The ingress CoS mutation configuration propagates without limit through port groups, member ports, and port-channel interfaces, regardless of whether or not the ports are configured to trust CoS or are configured as IEEE 802.1Q tunnel ports.
An EtherChannel where you want to configure ingress CoS mutation must not have member ports
that are in port groups containing member ports of other EtherChannels that have member ports that do not support ingress CoS mutation. (This restriction extends without limit through all port-group-linked member ports and port-channel-interface-linked ports.)
A port where you want to configure ingress CoS mutation must not be in a port group that has a
member port of an EtherChannel that has members that do not support ingress CoS mutation. (This restriction extends without limit through all port-group-linked member ports and port-channel-interface-linked ports.)
There can be only be one ingress CoS mutation configuration applied to all port-group-linked
member ports and port-channel-interface-linked ports.
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Configuring Ingress CoS Mutation Maps

To configure an ingress CoS mutation map, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos map cos-mutation
mutation_map_name mutated_cos1 mutated_cos2 mutated_cos3 mutated_cos4 mutated_cos5 mutated_cos6 mutated_cos7 mutated_cos8
Router(config)# no mls qos map cos-mutation map_name
Router(config)# end
Router# show mls qos maps cos-mutation
This example shows how to configure a CoS mutation map named testmap:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map cos-mutation testmap 4 5 6 7 0 1 2 3 Router(config)# end Router#
Configuring PFC QoS
Configures an ingress CoS mutation map. You must enter 8 mutated CoS values to which PFC QoS maps ingress CoS values 0 through 7.
Deletes the named map.
Exits configuration mode.
Verifies the configuration.
This example shows how to verify the map configuration:
Router(config)# show mls qos maps cos-mutation COS mutation map testmap cos-in : 0 1 2 3 4 5 6 7
-----------------------------------­cos-out : 4 5 6 7 0 1 2 3 Router#

Applying Ingress CoS Mutation Maps to IEEE 802.1Q Tunnel Ports

To attach an ingress CoS mutation map to an IEEE 802.1Q tunnel port, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{type1slot/port} | {port-channel number}}
Router(config-if)# mls qos cos-mutation mutation_map_name
Router(config-if)# no mls qos cos-mutation mutation_map_name
Router(config-if)# end
Router# show running-config interface
1
{{type Router# show mls qos maps cos-mutation
1. type = gigabitethernet or tengigabitethernet
slot/port} | {port-channel number}}
Selects the interface to configure.
Attaches an ingress CoS mutation map to the interface.
Removes the ingress CoS mutation map from the interface.
Exits configuration mode.
Verifies the configuration.
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This example shows how to attach the ingress CoS mutation map named testmap to Gigabit Ethernet port 1/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface gigabitethernet 1/1 Router(config-if)# mls qos cos-mutation testmap Router(config-if)# end Router# show mls qos maps cos-mutation COS mutation map testmap cos-in : 0 1 2 3 4 5 6 7
-----------------------------------­cos-out : 4 5 6 7 0 1 2 3
testmap is attached on the following interfaces Gi1/1 Router#

Configuring DSCP Value Maps

These sections describe how DSCP values are mapped to other values:
Mapping Received CoS Values to Internal DSCP Values, page 42-86
Mapping Received IP Precedence Values to Internal DSCP Values, page 42-87
Chapter 42 Configuring PFC QoS
Configuring DSCP Markdown Values, page 42-87
Mapping Internal DSCP Values to Egress CoS Values, page 42-89

Mapping Received CoS Values to Internal DSCP Values

To configure the mapping of received CoS values to the DSCP value that PFC QoS uses internally on the PFC, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos map cos-dscp dscp1 dscp2 dscp3 dscp4 dscp5 dscp6 dscp7 dscp8
Router(config)# no mls qos map cos-dscp
Router(config)# end
Router# show mls qos maps
This example shows how to configure the received CoS to internal DSCP map:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map cos-dscp 0 1 2 3 4 5 6 7 Router(config)# end Router#
Configures the received CoS to internal DSCP map. You must enter 8 DSCP values to which PFC QoS maps CoS values 0 through 7.
Reverts to the default map.
Exits configuration mode.
Verifies the configuration.
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This example shows how to verify the configuration:
Router# show mls qos maps | begin Cos-dscp map Cos-dscp map: cos: 0 1 2 3 4 5 6 7
---------------------------------­ dscp: 0 1 2 3 4 5 6 7 <...Output Truncated...> Router#

Mapping Received IP Precedence Values to Internal DSCP Values

To configure the mapping of received IP precedence values to the DSCP value that PFC QoS uses internally on the PFC, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# mls qos map ip-prec-dscp dscp1 dscp2 dscp3 dscp4 dscp5 dscp6 dscp7 dscp8
Router(config)# no mls qos map ip-prec-dscp
Router(config)# end
Router# show mls qos maps
Configures the received IP precedence to internal DSCP map. You must enter 8 internal DSCP values to which PFC QoS maps received IP precedence values 0 through 7.
Reverts to the default map.
Exits configuration mode.
Verifies the configuration.
Configuring PFC QoS
This example shows how to configure the received IP precedence to internal DSCP map:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map ip-prec-dscp 0 1 2 3 4 5 6 7 Router(config)# end Router#
This example shows how to verify the configuration:
Router# show mls qos maps | begin IpPrecedence-dscp map IpPrecedence-dscp map: ipprec: 0 1 2 3 4 5 6 7
---------------------------------­ dscp: 0 1 2 3 4 5 6 7 <...Output Truncated...> Router#

Configuring DSCP Markdown Values

To configure the mapping of DSCP markdown values used by policers, perform this task:
Command Purpose
Step 1
Router(config)# mls qos map policed-dscp {normal-burst | max-burst} dscp1 [dscp2 [dscp3 [dscp4 [dscp5 [dscp6 [dscp7 [dscp8]]]]]]] to markdown_dscp
Router(config)# no mls qos map policed-dscp {normal-burst | max-burst}
Configures a DSCP markdown map.
Reverts to the default map.
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Command Purpose
Step 2
Step 3
Router(config)# end
Router# show mls qos maps
Chapter 42 Configuring PFC QoS
Exits configuration mode.
Verifies the configuration.
When configuring a DSCP markdown map, note the following information:
You can enter the normal-burst keyword to configure the markdown map used by the
exceed-action policed-dscp-transmit keywords.
You can enter the max-burst keyword to configure the markdown map used by the violate-action
policed-dscp-transmit keywords.
Note When you create a policer that does not use the pir keyword, and the maximum_burst_bytes
parameter is equal to the normal_burst_bytes parameter (which occurs if you do not enter the maximum_burst_bytes parameter), the exceed-action policed-dscp-transmit keywords cause PFC QoS to mark traffic down as defined by the policed-dscp max-burst markdown map.
To avoid out-of-sequence packets, configure the markdown maps so that conforming and
nonconforming traffic uses the same queue.
You can enter up to 8 DSCP values that map to a marked-down DSCP value.
You can enter multiple commands to map additional DSCP values to a marked-down DSCP value.
You can enter a separate command for each marked-down DSCP value.
Note Configure marked-down DSCP values that map to CoS values consistent with the markdown penalty.
This example shows how to map DSCP 1 to marked-down DSCP value 0:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map policed-dscp normal-burst 1 to 0 Router(config)# end Router#
This example shows how to verify the configuration:
Router# show mls qos map Normal Burst Policed-dscp map: (dscp= d1d2) d1 : d2 0 1 2 3 4 5 6 7 8 9
------------------------------------­ 0 : 00 01 02 03 04 05 06 07 08 09 1 : 10 11 12 13 14 15 16 17 18 19 2 : 20 21 22 23 24 25 26 27 28 29 3 : 30 31 32 33 34 35 36 37 38 39 4 : 40 41 42 43 44 45 46 47 48 49 5 : 50 51 52 53 54 55 56 57 58 59 6 : 60 61 62 63
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Maximum Burst Policed-dscp map: (dscp= d1d2) d1 : d2 0 1 2 3 4 5 6 7 8 9
------------------------------------­ 0 : 00 01 02 03 04 05 06 07 08 09 1 : 10 11 12 13 14 15 16 17 18 19 2 : 20 21 22 23 24 25 26 27 28 29 3 : 30 31 32 33 34 35 36 37 38 39 4 : 40 41 42 43 44 45 46 47 48 49 5 : 50 51 52 53 54 55 56 57 58 59 6 : 60 61 62 63 <...Output Truncated...> Router#
Note In the Policed-dscp displays, the marked-down DSCP values are shown in the body of the matrix; the
first digit of the original DSCP value is in the column labeled d1 and the second digit is in the top row. In the example shown, DSCP 41 maps to DSCP 41.

Mapping Internal DSCP Values to Egress CoS Values

To configure the mapping of the DSCP value that PFC QoS uses internally on the PFC to the CoS value used for egress LAN port scheduling and congestion avoidance, perform this task:
Configuring PFC QoS
Step 1
Step 2
Step 3
Command Purpose
Router(config)# mls qos map dscp-cos dscp1 [dscp2 [dscp3 [dscp4 [dscp5 [dscp6 [dscp7 [dscp8]]]]]]] to cos_value
Router(config)# no mls qos map dscp-cos
Router(config)# end
Router# show mls qos maps
Configures the internal DSCP to egress CoS map.
Reverts to the default map.
Exits configuration mode.
Verifies the configuration.
When configuring the internal DSCP to egress CoS map, note the following information:
You can enter up to 8 DSCP values that PFC QoS maps to a CoS value.
You can enter multiple commands to map additional DSCP values to a CoS value.
You can enter a separate command for each CoS value.
This example shows how to configure internal DSCP values 0, 8, 16, 24, 32, 40, 48, and 54 to be mapped to egress CoS value 0:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# mls qos map dscp-cos 0 8 16 24 32 40 48 54 to 0 Router(config)# end Router#
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This example shows how to verify the configuration:
Router# show mls qos map | begin Dscp-cos map Dscp-cos map: (dscp= d1d2) d1 : d2 0 1 2 3 4 5 6 7 8 9
------------------------------------­ 0 : 00 00 00 00 00 00 00 00 00 01 1 : 01 01 01 01 01 01 00 02 02 02 2 : 02 02 02 02 00 03 03 03 03 03 3 : 03 03 00 04 04 04 04 04 04 04 4 : 00 05 05 05 05 05 05 05 00 06 5 : 06 06 06 06 00 06 07 07 07 07 6 : 07 07 07 07 <...Output Truncated...> Router#
Note In the Dscp-cos map display, the CoS values are shown in the body of the matrix; the first digit of the
DSCP value is in the column labeled d1 and the second digit is in the top row. In the example shown, DSCP values 41 through 47 all map to CoS 05.

Configuring the Trust State of Ethernet LAN and OSM Ports

Chapter 42 Configuring PFC QoS
Step 1
Step 2
Step 3
Step 4
By default, all ports are untrusted. You can configure the port trust state on all Ethernet LAN ports and OSM ports.
Note On non-Gigabit Ethernet 1q4t/2q2t ports, you must repeat the trust configuration in a class map.
To configure the trust state of a port, perform this task:
Command Purpose
Router(config)# interface {{type1slot/port} | {port-channel number}}
Router(config-if)# mls qos trust [dscp | ip-precedence | cos
Router(config-if)# no mls qos trust
Router(config-if)# end
Router# show queueing interface type1 slot/port | include Trust state
1. type = ethernet, fastethernet, gigabitethernet, tengigabitethernet, ge-wan, pos, or atm.
2. Not supported for serial, pos or atm interface types.
2
]
Selects the interface to configure.
Configures the trust state of the port.
Reverts to the default trust state (untrusted).
Exits configuration mode.
Verifies the configuration.
When configuring the trust state of a port, note the following information:
With no other keywords, the mls qos trust command is equivalent to mls qos trust dscp.
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enable DSCP-based receive-queue drop thresholds on WS-X6708-10GE ports (see the “Configuring
DSCP-Based Queue Mapping” section on page 42-98). To avoid dropping traffic because of
inconsistent DSCP values when DSCP-based queue mapping is enabled, configure ports with the mls qos trust dscp command only when the received traffic carries DSCP values that you know to be consistent with network policy.
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The mls qos trust cos command enables CoS-based receive-queue drop thresholds. To avoid
dropping traffic because of inconsistent CoS values, configure ports with the mls qos trust cos command only when the received traffic is ISL or 802.1Q frames carrying CoS values that you know to be consistent with network policy.
With Release 12.2(17b)SXA and later releases, you can configure IEEE 8021.Q tunnel ports
configured with the mls qos trust cos command to use a mutated CoS value instead of the received CoS value (“Configuring Ingress CoS Mutation on IEEE 802.1Q Tunnel Ports” section on
page 42-83).
Use the no mls qos trust command to set the port state to untrusted.
This example shows how to configure Gigabit Ethernet port 1/1 with the trust cos keywords:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface gigabitethernet 1/1 Router(config-if)# mls qos trust cos Router(config-if)# end Router#
This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 1/1 | include trust Trust state: trust COS Router#
Configuring PFC QoS

Configuring the Ingress LAN Port CoS Value

Note Whether or not PFC QoS uses the CoS value applied with the mls qos cos command depends on the trust
state of the port and the trust state of the traffic received through the port. The mls qos cos command does not configure the trust state of the port or the trust state of the traffic received through the port.
To use the CoS value applied with the mls qos cos command as the basis of internal DSCP:
On a port that receives only untagged ingress traffic, configure the ingress port as trusted or
configure a trust CoS policy map that matches the ingress traffic.
On a port that receives tagged ingress traffic, configure a trust CoS policy map that matches the
ingress traffic.
You can configure the CoS value that PFC QoS assigns to untagged frames from ingress LAN ports configured as trusted and to all frames from ingress LAN ports configured as untrusted.
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Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {{type1slot/port} | {port-channel number}}
Router(config-if)# mls qos cos port_cos
Router(config-if)# no mls qos cos port_cos
Router(config-if)# end
Router# show queuing interface {ethernet | fastethernet | gigabitethernet} slot/port
1. type = ethernet, fastethernet, gigabitethernet, or tengigabitethernet
Chapter 42 Configuring PFC QoS
To configure the CoS value for an ingress LAN port, perform this task:
Selects the interface to configure.
Configures the ingress LAN port CoS value.
Reverts to the default port CoS value.
Exits configuration mode.
Verifies the configuration.
This example shows how to configure the CoS value 5 on Fast Ethernet port 5/24 and verify the configuration:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface fastethernet 5/24 Router(config-if)# mls qos cos 5 Router(config-if)# end Router# show queueing interface fastethernet 5/24 | include Default COS Default COS is 5 Router#

Configuring Standard-Queue Drop Threshold Percentages

These sections describe configuring standard-queue drop threshold percentages:
Configuring a Tail-Drop Receive Queue, page 42-93
Configuring a WRED-Drop Transmit Queue, page 42-94
Configuring a WRED-Drop and Tail-Drop Receive Queue, page 42-94
Configuring a WRED-Drop and Tail-Drop Transmit Queue, page 42-95
Configuring 1q4t/2q2t Tail-Drop Threshold Percentages, page 42-96
Note Enter the show queueing interface {ethernet | fastethernet | gigabitethernet |
tengigabitethernet} slot/port | include type command to see the queue structure of a port.
1p1q0t ports have no configurable thresholds.
1p3q1t (transmit), 1p2q1t (transmit), and 1p1q8t (receive) ports also have nonconfigurable
tail-drop thresholds.
When configuring thresholds, note the following information:
Queue number 1 is the lowest-priority standard queue.
Higher-numbered queues are higher priority standard queues.
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When you configure multiple-threshold standard queues, note the following information:
The first percentage that you enter sets the lowest-priority threshold.
The second percentage that you enter sets the next highest-priority threshold.
The last percentage that you enter sets the highest-priority threshold.
The percentages range from 1 to 100. A value of 10 indicates a threshold when the buffer is
10-percent full.
Always set highest-numbered threshold to 100 percent.
When configuring the WRED-drop thresholds, note the following information:
Each WRED-drop threshold has a low-WRED and a high-WRED value.
Low-WRED and high-WRED values are a percentage of the queue capacity (the range is from 1
to 100).
The low-WRED value is the traffic level under which no traffic is dropped. The low-WRED value
must be lower than the high-WRED value.
The high-WRED value is the traffic level above which all traffic is dropped.
Traffic in the queue between the low- and high-WRED values has an increasing chance of being
dropped as the queue fills.
Configuring PFC QoS

Configuring a Tail-Drop Receive Queue

These port types have only tail-drop thresholds in their receive-queues:
1q2t
1p1q4t
2q8t
1q8t
To configure the drop thresholds, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {fastethernet | gigabitethernet} slot/port
Router(config-if)# rcv-queue threshold queue_id thr1% thr2% thr3% thr4% {thr5% thr6% thr7% thr8%}
Router(config-if)# no rcv-queue threshold [queue_id]
Router(config-if)# end
Router# show queueing interface {fastethernet | gigabitethernet} slot/port
Selects the interface to configure.
Configures the receive-queue tail-drop threshold percentages.
Reverts to the default receive-queue tail-drop threshold percentages.
Exits configuration mode.
Verifies the configuration.
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This example shows how to configure the receive-queue drop thresholds for Gigabit Ethernet port 1/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface gigabitethernet 1/1 Router(config-if)# rcv-queue threshold 1 60 75 85 100 Router(config-if)# end Router#
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This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 1/1 | begin Receive queues Receive queues [type = 1p1q4t]: Queue Id Scheduling Num of thresholds
----------------------------------------­ 1 Standard 4 2 Priority 1
Trust state: trust COS
queue tail-drop-thresholds
-------------------------­ 1 60[1] 75[2] 85[3] 100[4] <...Output Truncated...> Router#

Configuring a WRED-Drop Transmit Queue

These port types have only WRED-drop thresholds in their transmit queues:
1p2q2t (transmit)
1p2q1t (transmit)
Chapter 42 Configuring PFC QoS
Command Purpose
Step 1
Step 2
Step 3
Step 4
Step 5
Router(config)# interface type1 slot/port
Router(config-if)# wrr-queue random-detect min-threshold queue_id thr1% [thr2%]
Router(config-if)# no wrr-queue random-detect min-threshold [queue_id]
Router(config-if)# wrr-queue random-detect max-threshold queue_id thr1% [thr2%]
Router(config-if)# no wrr-queue random-detect max-threshold [queue_id]
Router(config-if)# end
Router# show queueing interface type1 slot/port
1. type = fastethernet, gigabitethernet, or tengigabitethernet
Selects the interface to configure.
Configures the low WRED-drop thresholds.
Reverts to the default low WRED-drop thresholds.
Configures the high WRED-drop thresholds.
Reverts to the default high WRED-drop thresholds.
Exits configuration mode.
Verifies the configuration.

Configuring a WRED-Drop and Tail-Drop Receive Queue

These port types have both WRED-drop and tail-drop thresholds in their receive queues:
8q4t (receive)
8q8t (receive)
1p1q8t (receive)
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To configure the drop thresholds, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Router(config)# interface type1 slot/port
Router(config-if)# rcv-queue threshold queue_id thr1% thr2% thr3% thr4% thr5% thr6% thr7% thr8%
Router(config-if)# no rcv-queue threshold [queue_id]
Router(config-if)# rcv-queue random-detect
min-threshold queue_id thr1% thr2% thr3% thr4% thr5% thr6% thr7% thr8%
Router(config-if)# no rcv-queue random-detect min-threshold [queue_id]
Router(config-if)# rcv-queue random-detect max-threshold queue_id thr1% thr2% thr3% thr4%
thr5% thr6% thr7% thr8%
Router(config-if)# no rcv-queue random-detect max-threshold [queue_id]
Router(config-if)# rcv-queue random-detect queue_id
Router(config-if)# no rcv-queue random-detect [queue_id]
Router(config-if)# end
Router# show queueing interface type1 slot/port
1. type = fastethernet, gigabitethernet, or tengigabitethernet
Configuring PFC QoS
Selects the interface to configure.
Configures the tail-drop thresholds.
Reverts to the default tail-drop thresholds.
Configures the low WRED-drop thresholds.
Reverts to the default low WRED-drop thresholds.
Configures the high WRED-drop thresholds.
Reverts to the default high WRED-drop thresholds.
Enables WRED-drop thresholds.
Enables tail-drop thresholds.
Exits configuration mode.
Verifies the configuration.

Configuring a WRED-Drop and Tail-Drop Transmit Queue

These port types have both WRED-drop and tail-drop thresholds in their transmit queues:
1p3q1t (transmit)
1p3q8t (transmit)
1p7q8t (transmit)
To configure the drop thresholds, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Router(config)# interface type1 slot/port
Router(config-if)# wrr-queue threshold queue_id thr1% [thr2% thr3% thr4% thr5% thr6% thr7% thr8%]
Router(config-if)# no wrr-queue threshold [queue_id]
Router(config-if)# wrr-queue random-detect
min-threshold queue_id thr1% [thr2% thr3% thr4% thr5% thr6% thr7% thr8%]
Router(config-if)# no wrr-queue random-detect min-threshold [queue_id]
Selects the interface to configure.
Configures the tail-drop thresholds.
Reverts to the default tail-drop thresholds.
Configures the low WRED-drop thresholds.
Reverts to the default low WRED-drop thresholds.
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Command Purpose
Step 4
Step 5
Step 6
Step 7
Router(config-if)# wrr-queue random-detect max-threshold queue_id thr1% [thr2% thr3% thr4%
thr5% thr6% thr7% thr8%]
Router(config-if)# no wrr-queue random-detect max-threshold [queue_id]
Router(config-if)# wrr-queue random-detect queue_id
Router(config-if)# no wrr-queue random-detect [queue_id]
Router(config-if)# end
Router# show queueing interface type1 slot/port
1. type = fastethernet, gigabitethernet, or tengigabitethernet
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Configures the high WRED-drop thresholds.
Reverts to the default high WRED-drop thresholds.
Enables WRED-drop thresholds.
Enables tail-drop thresholds.
Exits configuration mode.
Verifies the configuration.
This example shows how to configure the low-priority transmit queue high-WRED-drop thresholds for Gigabit Ethernet port 1/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface gigabitethernet 1/1 Router(config-if)# wrr-queue random-detect max-threshold 1 70 70 Router(config-if)# end Router#
This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 1/1 | begin Transmit queues Transmit queues [type = 1p2q2t]: Queue Id Scheduling Num of thresholds
----------------------------------------­ 1 WRR low 2 2 WRR high 2 3 Priority 1
queue random-detect-max-thresholds
---------------------------------­ 1 40[1] 70[2] 2 40[1] 70[2] <...Output Truncated...> Router#

Configuring 1q4t/2q2t Tail-Drop Threshold Percentages

On 1q4t/2q2t ports, the receive- and transmit-queue drop thresholds have this relationship:
Receive queue 1 (standard) threshold 1 = transmit queue 1 (standard low priority) threshold 1
Receive queue 1 (standard) threshold 2 = transmit queue 1 (standard low priority) threshold 2
Receive queue 1 (standard) threshold 3 = transmit queue 2 (standard high priority) threshold 1
Receive queue 1 (standard) threshold 4 = transmit queue 2 (standard high priority) threshold 2
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To configure tail-drop threshold percentages for the standard receive and transmit queues on 1q4t/2q2t LAN ports, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface {ethernet | fastethernet | gigabitethernet} slot/port
Router(config-if)# wrr-queue threshold queue_id thr1% thr2%
Router(config-if)# no wrr-queue threshold [queue_id]
Router(config-if)# end
Router# show queueing interface {ethernet | fastethernet | gigabitethernet} slot/port
When configuring the receive- and transmit-queue tail-drop thresholds, note the following information:
You must use the transmit queue and threshold numbers.
The queue_id is 1 for the standard low-priority queue and 2 for the standard high-priority queue.
Configuring PFC QoS
Selects the interface to configure.
Configures the receive- and transmit-queue tail-drop thresholds.
Reverts to the default receive- and transmit-queue tail-drop thresholds.
Exits configuration mode.
Verifies the configuration.
The percentages range from 1 to 100. A value of 10 indicates a threshold when the buffer is
10-percent full.
Always set threshold 2 to 100 percent.
Ethernet and Fast Ethernet 1q4t ports do not support receive-queue tail-drop thresholds.
This example shows how to configure receive queue 1/threshold 1 and transmit queue 1/threshold 1 for Gigabit Ethernet port 2/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface gigabitethernet 2/1 Router(config-if)# wrr-queue threshold 1 60 100 Router(config-if)# end Router#
This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 2/1 Transmit queues [type = 2q2t]:
<...Output Truncated...>
queue tail-drop-thresholds
-------------------------­ 1 60[1] 100[2] 2 40[1] 100[2]
<...Output Truncated...>
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Receive queues [type = 1q4t]:
<...Output Truncated...>
queue tail-drop-thresholds
-------------------------­ 1 60[1] 100[2] 40[3] 100[4] <...Output Truncated...> Router#
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Mapping QoS Labels to Queues and Drop Thresholds

These sections describe how to map QoS labels to queues and drop thresholds:
Note Enter the show queueing interface {ethernet | fastethernet | gigabitethernet | tengigabitethernet}
slot/port | include type command to see the queue structure of a port.
These sections describe how to map QoS labels to queues and drop thresholds:
Queue and Drop Threshold Mapping Guidelines and Restrictions, page 42-98
Configuring DSCP-Based Queue Mapping, page 42-98
Configuring CoS-Based Queue Mapping, page 42-104

Queue and Drop Threshold Mapping Guidelines and Restrictions

When mapping QoS labels to queues and thresholds, note the following information:
When SRR is enabled, you cannot map any CoS values or DSCP values to strict-priority queues.
Queue number 1 is the lowest-priority standard queue.
Higher-numbered queues are higher priority standard queues.
Chapter 42 Configuring PFC QoS
You can map up to 8 CoS values to a threshold.
You can map up to 64 DSCP values to a threshold.
Threshold 0 is a nonconfigurable 100-percent tail-drop threshold on these port types:
1p1q0t (receive)
1p1q8t (receive)
1p3q1t (transmit)
1p2q1t (transmit)
The standard queue thresholds can be configured as either tail-drop or WRED-drop thresholds on
these port types:
1p1q8t (receive)
1p3q1t (transmit)
1p3q8t (transmit)
1p7q1t (transmit)

Configuring DSCP-Based Queue Mapping

These sections describe how to configure DSCP-based queue mapping:
Configuring Ingress DSCP-Based Queue Mapping, page 42-99
Mapping DSCP Values to Standard Transmit-Queue Thresholds, page 42-102
Mapping DSCP Values to the Transmit Strict-Priority Queue, page 42-103
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Note DSCP-based queue mapping is supported on WS-X6708-10GE ports.
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Enabling DSCP-Based Queue Mapping
To enable DSCP-based queue mapping, perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface tengigabitethernet slot/port
Router(config-if)# mls qos queue-mode mode-dscp
Router(config-if)# no mls qos queue-mode mode-dscp
Router(config-if)# end
Router# show queueing interface tengigabitethernet slot/port | include Queueing Mode
This example shows how to enable DSCP-based queue mapping on 10-Gigabit Ethernet port 6/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface tengigabitethernet 6/1 Router(config-if)# mls qos queue-mode mode-dscp Router(config-if)# end
Configuring PFC QoS
Selects the interface to configure.
Enables DSCP-based queue mapping.
Reverts to CoS-based queue mapping.
Exits configuration mode.
Verifies the configuration.
This example shows how to verify the configuration:
Router# show queueing interface tengigabitethernet 6/1 | include Queueing Mode
Queueing Mode In Tx direction: mode-dscp Queueing Mode In Rx direction: mode-dscp
Configuring Ingress DSCP-Based Queue Mapping
Ingress DSCP-to-queue mapping is supported only on ports configured to trust DSCP.
These sections describe how to configure ingress DSCP-based queue mapping:
Enabling DSCP-Based Queue Mapping, page 42-99
Mapping DSCP Values to Standard Receive-Queue Thresholds, page 42-100
Configuring the Port to Trust DSCP
To configure the port to trust DSCP perform this task:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface tengigabitethernet slot/port
Router(config-if)# mls qos trust dscp
Router(config-if)# no mls qos trust
Router(config-if)# end
Router# show queueing interface tengigabitethernet slot/port | include Trust state
Selects the interface to configure.
Configures the port to trust received DSCP values.
Reverts to the default trust state (untrusted).
Exits configuration mode.
Verifies the configuration.
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This example shows how to configure 10-Gigabit Ethernet port 6/1 port 6/1 to trust received DSCP values:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z.
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Command Purpose
Step 1
Step 2
Step 3
Step 4
Router(config)# interface tengigabitethernet slot/port
Router(config-if)# rcv-queue dscp-map queue_# threshold_# dscp1 [dscp2 [dscp3 [dscp4 [dscp5 [dscp6 [dscp7 [dscp8]]]]]]]
Router(config-if)# no rcv-queue dscp-map
Router(config-if)# end
Router# show queueing interface tengigabitethernet slot/port
Chapter 42 Configuring PFC QoS
Router(config)# interface gigabitethernet 6/1 Router(config-if)# mls qos trust dscp Router(config-if)# end Router#
This example shows how to verify the configuration:
Router# show queueing interface gigabitethernet 6/1 | include Trust state Trust state: trust DSCP
Mapping DSCP Values to Standard Receive-Queue Thresholds
To map DSCP values to the standard receive-queue thresholds, perform this task:
Selects the interface to configure.
Maps DSCP values to the standard receive queue thresholds.
Reverts to the default mapping.
Exits configuration mode.
Verifies the configuration.
When mapping DSCP values, note the following information:
You can enter up to 8 DSCP values that map to a queue and threshold.
You can enter multiple commands to map additional DSCP values to the queue and threshold.
You must enter a separate command for each queue and threshold.
This example shows how to map the DSCP values 0 and 1 to threshold 1 in the standard receive queue for 10-Gigabit Ethernet port 6/1 port 6/1:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# interface tengigabitethernet 6/1 Router(config-if)# rcv-queue dscp-map 1 1 0 1 Router(config-if)# end Router#
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