Juniper EX9200 Series Overview Manual

Class of Service Overview and Examples for EX9200 Switches

Published: 2013-08-28

Juniper Networks, Inc. 1194 North Mathilda Avenue Sunnyvale, California 94089 USA 408-745-2000 www.juniper.net

This product includes the Envoy SNMP Engine,developed by Epilogue Technology, an Integrated Systems Company. Copyright © 1986-1997, Epilogue Technology Corporation. All rights reserved. This program and its documentation were developed at private expense, and no part of them is in the public domain.

This product includes FreeBSD software developed by the University of California, Berkeley, and its contributors. All of the documentation and software included in the 4.4BSD and 4.4BSD-Lite Releases is copyrighted by the Regents of the University of California. Copyright © 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994. The Regents of the University of California. All rights reserved.

GateD software copyright © 1995, the Regents of the University. All rights reserved. Gate Daemon was originated and developed through release 3.0 by Cornell University and its collaborators. Gated is based on Kirton’s EGP, UC Berkeley’s routing daemon (routed), and DCN’s HELLO routing protocol. Development of Gated has been supported in part by the National Science Foundation. Portions of the GateD software copyright © 1988, Regents of the University of California. All rights reserved. Portions of the GateD software copyright © 1991, D. L. S. Associates.

Juniper Networks, Junos, Steel-Belted Radius, NetScreen, and ScreenOS are registered trademarks of Juniper Networks, Inc. in the United States and other countries. The Juniper Networks Logo, the Junos logo, and JunosE are trademarks of Juniper Networks, Inc. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.

Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify, transfer, or otherwise revise this publication without notice.

Products made or sold by Juniper Networks or components thereof might be covered by one or more of the following patents that are owned by or licensed to Juniper Networks: U.S. Patent Nos. 5,473,599, 5,905,725, 5,909,440, 6,192,051, 6,333,650, 6,359,479, 6,406,312, 6,429,706, 6,459,579, 6,493,347, 6,538,518, 6,538,899, 6,552,918, 6,567,902, 6,578,186, and 6,590,785.

Class of Service Overview and Examples for EX9200 Switches

The information in this document is current as of the date on the title page.

YEAR 2000 NOTICE

Juniper Networks hardware and software products are Year 2000 compliant. Junos OS has no known time-related limitations through the year 2038. However, the NTP application is known to have some difficulty in the year 2036.

END USER LICENSE AGREEMENT

The Juniper Networks product that is the subject of this technical documentation consists of (or is intended for use with) Juniper Networks software. Use of such software is subject to the terms and conditions of the End User License Agreement (“EULA”) posted at

http://www.juniper.net/support/eula.html. By downloading, installing or using such software, you agree to the terms and conditions of

that EULA.

Table of Contents

About the Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Documentation and Release Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Supported Platforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Using the Examples in This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Merging a Full Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Merging a Snippet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Documentation Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Documentation Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii

Requesting Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Self-Help Online Tools and Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Opening a Case with JTAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv

Part 1 Overview

Chapter 1 CoS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

CoS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

CoS Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Understanding Packet Flow Across a Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Junos CoS Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Default CoS Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

CoS Applications Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Interface Types That Do Not Support CoS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

VPLS and Default CoS Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Chapter 2 CoS Input and Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

CoS Inputs and Outputs Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Chapter 3 Packet Flow Through the CoS Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Packet Flow Through the CoS Process Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Part 2 Configuration

Chapter 4 Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

[edit chassis] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

[edit class-of-service] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

[edit firewall] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Common Firewall Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Common IP Firewall Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Common IPv4 Firewall Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Common IP Firewall Match Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Common IPv4 Firewall Match Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Common Layer 2 Firewall Match Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Class of Service Overview and Examples for EX9200 Switches

Complete [edit firewall] Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

[edit interfaces] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

List of Figures

Part 1 Overview

Chapter 1 CoS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 1: Packet Flow Across the Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Chapter 3 Packet Flow Through the CoS Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 2: CoS Classifier, Queues, and Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 3: Packet Flow Through CoS Configurable Components . . . . . . . . . . . . . . . 16

Class of Service Overview and Examples for EX9200 Switches

List of Tables

About the Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Table 1: Notice Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Table 2: Text and Syntax Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Part 1 Overview

Chapter 1 CoS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Table 3: Default VPLS Classifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 2 CoS Input and Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 4: CoS Mappings—Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Class of Service Overview and Examples for EX9200 Switches

About the Documentation

•

Documentation and Release Notes on page ix

•

Supported Platforms on page ix

•

Using the Examples in This Manual on page ix

•

Documentation Conventions on page xi

•

Documentation Feedback on page xii

•

Requesting Technical Support on page xiii

Documentation and Release Notes

To obtain the most current version of all Juniper Networks®technical documentation, see the product documentation page on the Juniper Networks website at

http://www.juniper.net/techpubs/.

If the information in the latest release notes differs from the information in the documentation, follow the product Release Notes.

Juniper Networks Books publishes books by Juniper Networks engineers and subject matter experts. These books go beyond the technical documentation to explore the nuances of network architecture, deployment, and administration. The current list can be viewed at http://www.juniper.net/books.

Supported Platforms

For the features described in this document, the following platforms are supported:

•

EX Series

Using the Examples in This Manual

If you want to use the examples in this manual, you can use the load merge or the load

merge relative command. These commands cause the software to merge the incoming

configuration into the current candidate configuration. The example does not become active until you commit the candidate configuration.

If the example configuration contains the top level of the hierarchy (or multiple hierarchies), the example is a full example. In this case, use the load merge command.

Class of Service Overview and Examples for EX9200 Switches

If the example configuration does not start at the top level of the hierarchy, the example is a snippet. In this case, use the load merge relative command. These procedures are described in the following sections.

Merging a Full Example

To merge a full example, follow these steps:

1. From the HTML or PDF version of the manual, copy a configuration example into a

text file, save the file with a name, and copy the file to a directory on your routing platform.

For example,copy the following configuration to a file and name the file ex-script.conf. Copy the ex-script.conf file to the /var/tmp directory on your routing platform.

system {

scripts {

commit {

file ex-script.xsl;

}

} interfaces {

fxp0 {

disable; unit 0 {

family inet {

address 10.0.0.1/24;

}

Merging a Snippet

2. Merge the contents of the file into your routing platform configuration by issuing the

load merge configuration mode command:

[edit] user@host# load merge /var/tmp/ex-script.conf load complete

To merge a snippet, follow these steps:

1. From the HTML or PDF version of the manual, copy a configuration snippet into a text

file, save the file with a name, and copy the file to a directory on your routing platform.

For example, copy the following snippet to a file and name the file

ex-script-snippet.conf. Copy the ex-script-snippet.conf file to the /var/tmp directory

on your routing platform.

commit {

file ex-script-snippet.xsl; }

2. Move to the hierarchy level that is relevant for this snippet by issuing the following

configuration mode command:

[edit] user@host# edit system scripts [edit system scripts]

3. Merge the contents of the file into your routing platform configuration by issuing the

load merge relative configuration mode command:

[edit system scripts] user@host# load merge relative /var/tmp/ex-script-snippet.conf load complete

For more information about the load command, see the CLI User Guide.

Documentation Conventions

Table 1 on page xi defines notice icons used in this guide.

Table 1: Notice Icons

About the Documentation

DescriptionMeaningIcon

Table 2 on page xi defines the text and syntax conventions used in this guide.

Table 2: Text and Syntax Conventions

Represents text that you type.Bold text like this

Indicates important features or instructions.Informational note

Indicates a situation that might result in loss of data or hardware damage.Caution

Alerts you to the risk of personal injury or death.Warning

Alerts you to the risk of personal injury from a laser.Laser warning

ExamplesDescriptionConvention

To enter configuration mode, type theconfigure command:

user@host> configure

Fixed-width text like this

Italic text like this

Represents output that appears on the terminal screen.

•

Introduces or emphasizes important new terms.

•

Identifies guide names.

•

Identifies RFC and Internet draft titles.

user@host> show chassis alarms

No alarms currently active

•

A policy term is a named structure that defines match conditions and actions.

•

Junos OS CLI User Guide

•

RFC 1997, BGP Communities Attribute

Class of Service Overview and Examples for EX9200 Switches

Table 2: Text and Syntax Conventions (continued)

ExamplesDescriptionConvention

Italic text like this

Text like this

| (pipe symbol)

# (pound sign)

[ ] (square brackets)

Indention and braces ( { } )

; (semicolon)

Represents variables (options for which you substitute a value) in commands or configuration statements.

Represents names of configuration statements, commands, files, and directories;configurationhierarchylevels; or labels on routing platform components.

Indicates a choice between the mutually exclusivekeywords or variables on either side of the symbol. The set of choices is often enclosed in parentheses for clarity.

same line as the configuration statement to which it applies.

Enclose a variable for which you can substitute one or more values.

Identify a level in the configuration hierarchy.

Identifies a leaf statement at a configuration hierarchy level.

Configure the machine’s domain name:

[edit] root@# set system domain-name

domain-name

•

To configure a stub area, include the

stub statement at the[edit protocols ospf area area-id] hierarchy level.

•

The console port is labeled CONSOLE.

stub <default-metric metric>;Enclose optional keywords or variables.< > (angle brackets)

broadcast | multicast

(string1 | string2 | string3)

rsvp { # Required for dynamic MPLS onlyIndicates a comment specified on the

community name members [ community-ids ]

[edit] routing-options {

static {

route default {

nexthop address; retain;

}

GUI Conventions

Bold text like this

> (bold right angle bracket)

Documentation Feedback

We encourage you to provide feedback, comments, and suggestions so that we can improve the documentation. You can send your comments to

techpubs-comments@juniper.net, or fill out the documentation feedback form at

Representsgraphicaluser interface (GUI) items you click or select.

Separates levels in a hierarchy of menu selections.

•

In the Logical Interfaces box, select

All Interfaces.

•

To cancel the configuration, click

Cancel.

In the configuration editor hierarchy, select Protocols>Ospf.

https://www.juniper.net/cgi-bin/docbugreport/ . If you are using e-mail, be sure to include

the following information with your comments:

•

Document or topic name

•

URL or page number

•

Software release version (if applicable)

Requesting Technical Support

Technical product support is availablethrough the Juniper Networks Technical Assistance Center (JTAC). If you are a customer with an active J-Care or JNASC support contract, or are covered under warranty, and need post-sales technical support, you can access our tools and resources online or open a case with JTAC.

•

JTAC policies—For a complete understanding of our JTAC procedures and policies, review the JTAC User Guide located at

http://www.juniper.net/us/en/local/pdf/resource-guides/7100059-en.pdf.

About the Documentation

•

Product warranties—For product warranty information, visit

http://www.juniper.net/support/warranty/.

•

JTAC hours of operation—The JTAC centers have resources available 24 hours a day, 7 days a week, 365 days a year.

Self-Help Online Tools and Resources

For quick and easy problem resolution, Juniper Networks has designed an online self-service portal called the Customer Support Center (CSC) that provides you with the following features:

•

Find CSC offerings: http://www.juniper.net/customers/support/

•

Search for known bugs: http://www2.juniper.net/kb/

•

Find product documentation: http://www.juniper.net/techpubs/

•

Find solutions and answer questions using our Knowledge Base: http://kb.juniper.net/

•

Download the latest versions of software and review release notes:

http://www.juniper.net/customers/csc/software/

•

Search technical bulletins for relevant hardware and software notifications:

https://www.juniper.net/alerts/

•

Join and participate in the Juniper Networks Community Forum:

http://www.juniper.net/company/communities/

•

Open a case online in the CSC Case Management tool: http://www.juniper.net/cm/

To verify service entitlement by product serial number, use our Serial Number Entitlement (SNE) Tool: https://tools.juniper.net/SerialNumberEntitlementSearch/

Class of Service Overview and Examples for EX9200 Switches

Opening a Case with JTAC

You can open a case with JTAC on the Web or by telephone.

•

Use the Case Management tool in the CSC at http://www.juniper.net/cm/.

•

Call 1-888-314-JTAC (1-888-314-5822 toll-free in the USA, Canada, and Mexico).

For international or direct-dial options in countries without toll-free numbers, see

http://www.juniper.net/support/requesting-support.html.

PART 1

Overview

•

CoS Overview on page 3

•

CoS Input and Output Configuration on page 13

•

Packet Flow Through the CoS Process on page 15

Class of Service Overview and Examples for EX9200 Switches

CHAPTER 1

CoS Overview

•

CoS Overview on page 3

•

CoS Standards on page 4

•

Understanding Packet Flow Across a Network on page 4

•

Junos CoS Components on page 5

•

Default CoS Settings on page 6

•

CoS Applications Overview on page 8

•

Interface Types That Do Not Support CoS on page 9

•

VPLS and Default CoS Classification on page 10

CoS Overview

When a network experiences congestion and delay, some packets must be dropped. The Juniper Networks®Junos®operating system (Junos OS) class of service (CoS) enables you to divide traffic into classes and offer various levels of throughput and packet loss when congestion occurs. This allows packet loss to happen according to rules that you configure.

For interfaces that carry IPv4, IPv6, and MPLS traffic, you can configure the Junos OS CoS features to provide multiple classes of service for different applications. On the routing device, you can configure multiple forwarding classes for transmitting packets, define which packets are placed into each output queue, schedule the transmission service level for each queue, and manage congestion using a random early detection (RED) algorithm.

The Junos OS CoS features provide a set of mechanisms that you can use to provide differentiated services when best-effort traffic delivery is insufficient. In designing CoS applications, you must give careful consideration to your service needs, and you must thoroughly plan and design your CoS configuration to ensure consistency across all routing devices in a CoS domain. You must also consider all the routing devices and other networking equipment in the CoS domain to ensure interoperabilityamong all equipment.

Because Juniper Networks routing devices implement CoS in hardware rather than in software, you can experiment with and deploy CoS features without adversely affecting packet forwarding and routing performance.

Class of Service Overview and Examples for EX9200 Switches

CoS Standards

The standards for Juniper Networks®Junos®operatingsystem (Junos OS) class of service (CoS) capabilities are defined in the following RFCs:

•

RFC 2474, Definition of the Differentiated Services Field in the IPv4 and IPv6 Headers

•

RFC 2597, Assured Forwarding PHB Group

•

RFC 2598, An Expedited Forwarding PHB

•

RFC 2698, A Two Rate Three Color Marker

Understanding Packet Flow Across a Network

CoS works by examining traffic entering at the edge of your network. The edge routing devices classify traffic into defined service groups, to provide the special treatment of traffic across the network. For example, voice traffic can be sent across certain links, and data traffic can use other links. In addition, the data traffic streams can be serviced differently along the network path to ensure that higher-paying customers receive better service. As the traffic leaves the network at the far edge, you can reclassify the traffic.

To support CoS, you must configure each routing device in the network. Generally, each routing device examines the packets that enter it to determine their CoS settings. These settings then dictate which packets are first transmitted to the next downstream routing device. In addition, the routing devices at the edges of the network might be required to alter the CoS settings of the packets that enter the network from the customer or peer networks.

In Figure 1 on page 4, Router A is receiving traffic from a customer network. As each packet enters, Router A examines the packet’s current CoS settings and classifies the traffic into one of the groupings defined by the Internet service provider (ISP). This definition allows Router A to prioritize its resources for servicing the traffic streams it is receiving. In addition, Router A might alter the CoS settings (forwarding class and loss priority) of the packets to better match the ISP’s traffic groups. When Router B receives the packets, it examines the CoS settings, determines the appropriate traffic group, and processesthe packet according to those settings. It then transmits the packetsto RouterC, which performs the same actions. Router D also examines the packets and determines the appropriate group. Because Router D sits at the far end of the network, the ISP might decide once again to alter the CoS settings of the packets before Router D transmits them to the neighboring network.

Figure 1: Packet Flow Across the Network

Junos CoS Components

The Juniper Networks®Junos®operating system (Junos OS) CoS consists of many components that you can combine and tune to provide the level of services required by customers.

The Junos OS CoS components include:

•

Code-point aliases—A code-point alias assigns a name to a pattern of code-point bits. You can use this name instead of the bit pattern when you configure other CoS components, such as classifiers, drop-profile maps, and rewrite rules.

•

Classifiers—Packet classification refers to the examination of an incoming packet. This function associates the packet with a particular CoS servicing level. In the Junos OS, classifiers associate incoming packets with a forwarding class and loss priority and, based on the associated forwarding class, assign packets to output queues. Two general types of classifiers are supported:

•

Chapter 1: CoS Overview

Behavior aggregate or CoS value traffic classifiers—A behavior aggregate (BA) is a method of classification that operates on a packet as it enters the routing device. The CoS value in the packet header is examined, and this single field determines the CoS settings applied to the packet. BA classifiers allow you to set the forwarding class and loss priority of a packet based on the Differentiated Services code point (DSCP) value, DSCP IPv6 value, IP precedence value, MPLS EXP bits, and IEEE 802.1p value. The default classifier is based on the IP precedence value.

•

Multifield traffic classifiers—A multifield classifier is a second method for classifying traffic flows. Unlike a behavior aggregate, a multifield classifier can examine multiple fields in the packet. Examples of some fields that a multifield classifier can examine include the source and destination address of the packet as well as the source and destination port numbers of the packet. With multifield classifiers, you set the forwarding class and loss priority of a packet based on firewall filter rules.

•

Forwarding classes—The forwarding classes affect the forwarding, scheduling, and marking policies applied to packets as they transit a routing device. The forwarding class plus the loss priority define the per-hop behavior. Four categories of forwarding classes are supported: best effort, assured forwarding, expedited forwarding, and network control. For Juniper Networks M Series Multiservice Edge Routers, four forwarding classes are supported. You can configure up to one each of the four types of forwarding classes. For M120 and M320 Multiservice Edge Routers,Juniper Networks MX Series 3D Universal Edge Routers, Juniper Networks T Series Core Routers and EX Series switches, 16 forwarding classes are supported, so you can classify packets more granularly. For example, you can configure multiple classes of expedited forwarding (EF) traffic: EF, EF1, and EF2.

•

Loss priorities—Loss priorities allow you to set the priority of dropping a packet. Loss priority affects the scheduling of a packet without affecting the packet’s relative ordering. You can use the packet loss priority (PLP) bit as part of a congestion control strategy. You can use the loss priority setting to identify packets that have experienced congestion. Typically you mark packets exceeding some service level with a high loss

Class of Service Overview and Examples for EX9200 Switches

priority. You set loss priority by configuring a classifier or a policer. The loss priority is used later in the workflow to select one of the drop profiles used by RED.

•

Forwarding policy options—These options allow you to associate forwarding classes with next hops. Forwarding policy also allows you to create classification overrides, which assign forwarding classes to sets of prefixes.

•

Transmission scheduling and rate control—These parameters provide you with a variety of tools to manage traffic flows:

•

Queuing—After a packet is sent to the outgoing interface on a routing device, it is queued for transmission on the physical media. The amount of time a packet is queued on the routing device is determined by the availabilityof the outgoing physical media as well as the amount of traffic using the interface.

•

Schedulers—An individual routing device interface has multiple queues assigned to store packets. The routing device determines which queue to service based on a particular method of scheduling. This process often involves a determination of which type of packet should be transmitted before another.The Junos OS schedulers allow you to define the priority, bandwidth, delay buffer size, rate control status, and RED drop profiles to be applied to a particular queue for packet transmission.

Default CoS Settings

•

Fabric schedulers—For M320 and T Series routers only, fabric schedulers allow you to identify a packet as high or low priority based on its forwarding class, and to associate schedulers with the fabric priorities.

•

Policers for traffic classes—Policers allow you to limit traffic of a certain class to a specified bandwidth and burst size. Packets exceeding the policer limits can be discarded, or can be assigned to a different forwarding class, a different loss priority, or both. You define policers with filters that can be associated with input or output interfaces.

•

Rewrite rules—A rewrite rule sets the appropriate CoS bits in the outgoing packet. This allows the next downstream routing device to classify the packet into the appropriate service group. Rewriting, or marking, outbound packets is useful when the routing device is at the border of a network and must alter the CoS values to meet the policies of the targeted peer.

If you do not configure any CoS settings on your routing device, the software performs some CoS functions to ensure that user traffic and protocol packets are forwarded with minimum delay when the network is experiencing congestion. Some default mappings are automatically applied to each logical interface that you configure. Other default mappings, such as explicit default classifiers and rewrite rules, are in operation only if you explicitly associate them with an interface.

You can display default CoS settings by issuing the show class-of-service operational mode command. This section includes sample output displaying the defaultCoS settings. The sample output is truncated for brevity.

show class-of-service

user@host> show class-of-service

Default Forwarding Classes

Forwarding class Queue best-effort 0 expedited-forwarding 1 assured-forwarding 2 network-control 3

Default Code-Point Aliases

Code point type: dscp Alias Bit pattern af11 001010 af12 001100 ... Code point type: dscp-ipv6 ... Code point type: exp ... Code point type: ieee-802.1 ... Code point type: inet-precedence ...

Chapter 1: CoS Overview

Default Classifiers

Classifier: dscp-default, Code point type: dscp, Index: 7 ...

Classifier: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 8 ...

Classifier: exp-default, Code point type: exp, Index: 9 ...

Classifier: ieee8021p-default, Code point type: ieee-802.1, Index: 10 ...

Classifier: ipprec-default, Code point type: inet-precedence, Index: 11 ...

Classifier: ipprec-compatibility, Code point type: inet-precedence, Index: 12 ...

Default Frame Relay Loss Priority Map

Loss-priority-map: frame-relay-de-default, Code point type: frame-relay-de, Index: 13 Code point Loss priority 0 low 1 high

Default Rewrite Rules

Rewrite rule: dscp-default, Code point type: dscp, Index: 24 Forwarding class Loss priority Code point best-effort low 000000

Class of Service Overview and Examples for EX9200 Switches

best-effort high 000000 ...

Rewrite rule: dscp-ipv6-default, Code point type: dscp-ipv6, Index: 25 ...

Rewrite rule: exp-default, Code point type: exp, Index: 26 ...

Rewrite rule: ieee8021p-default, Code point type: ieee-802.1, Index: 27 ...

Rewrite rule: ipprec-default, Code point type: inet-precedence, Index: 28 ...

Default Drop Profile

Drop profile: <default-drop-profile>, Type: discrete, Index: 1 Fill level Drop probability 100 100

Default Schedulers

Scheduler map: <default>, Index: 2

Scheduler: <default-be>, Forwarding class: best-effort, Index: 17 Transmit rate: 95 percent, Rate Limit: none, Buffer size: 95 percent, Priority: low Drop profiles: Loss priority Protocol Index Name Low Any 1 <default-drop-profile> High Any 1 <default-drop-profile> ...

Documentation

Default Forwarding Classes•

• Default Behavior Aggregate Classification Overview

• Default Drop Profile

• Default Schedulers Overview

• Forwarding Classes and Fabric Priority Queues

CoS Applications Overview

You can configureCoS features to meet your application needs. Because the components are generic, you can use a single CoS configurationsyntaxacross multiple routing devices. CoS mechanisms are useful for two broad classes of applications. These applications can be referred to as in the box and across the network.

In-the-box applications use CoS mechanisms to provide special treatment for packets passing through a single node on the network. You can monitor the incoming traffic on each interface, using CoS to provide preferred service to some interfaces (that is, to some customers) while limiting the service provided to other interfaces. You can also filter outgoing traffic by the packet’s destination, thus providing preferred service to some destinations.

+ 50 hidden pages

Juniper EX9200 Series Overview Manual

Specifications and Main Features

Frequently Asked Questions

User Manual