Cabletron Systems 802.1Q User Manual

802.1Q VLAN
User’s Guide

9032599-02

NOTICE

Cabletron Systems reserves the right to make changes in specifications and other information
contained in this document without prior notice. The reader should in all cases consult Cabletron
Systems to determine whether any such changes have been made.

The hardware, firmware, or software described in this manual is subject to change without notice.
IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR ANY INCIDENTAL,

INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING BUT
NOT LIMITED TO LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MANUAL OR
THE INFORMATION CONTAINED IN IT, EVEN IF CABLETRON SYSTEMS HAS BEEN
ADVISED OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH
DAMAGES.



1999 by Cabletron Systems, Inc., P.O. Box 5005, Rochester, NH 03866-5005
All Rights Reserved
Printed in the United States of America

Order Number: 9032599-02 February 1999

Cabletron Systems

of Cabletron Systems, Inc.
All other product names mentioned in this manual may be trademarks or registered trademarks of

their respective companies.

and

S

ECUREFAST

are registered trademarks and

S

MARTSWITCH

is a trademark

802.1Q VLAN User’s Guide i

Notice

ii 802.1Q VLAN User’s Guide

CONTENTS

Figures ....................................................................................................vii

Tables.....................................................................................................viii

PREFACE

Using This Guide............................................................................ix

Structure of This Guide...................................................................ix

Related Documents.........................................................................x

Document Conventions...................................................................x

CHAPTER 1 VIRTUAL LOCAL AREA NETWORKS

1.1 Defining VLANs...........................................................................1-1

1.2 Types of VLANs...........................................................................1-3

1.2.1 802.1Q VLANs................................................................1-3

1.2.2 SecureFast VLANs .........................................................1-3

1.2.3 Other VLAN Strategies ...................................................1-3

1.3 Benefits and Restrictions.............................................................1-4

1.4 VLAN Terms................................................................................1-4

1.5 Getting Help.................................................................................1-7

CHAPTER 2 VLAN OPERATION

2.1 Description...................................................................................2-1

2.2 VLAN Components......................................................................2-1

2.3 Configuration Process.................................................................2-2

2.3.1 Defining a VLAN .............................................................2-2

2.3.2 Classifying Frames to a VLAN........................................2-2

2.3.3 Customizing the VLAN Forwarding List.......................... 2-3

2.4 VLAN Switch Operation...............................................................2-3

2.4.1 Receiving Frames from VLAN Ports...............................2-4

2.4.2 Forwarding Decisions .....................................................2-5

2.4.2.1 Broadcasts, Multicasts, and Unknown

Unicasts..........................................................2-5

2.4.2.2 Known Unicasts..............................................2-5

2.5 GARP Switch Operation..............................................................2-6

802.1Q VLAN User’s Guide iii

Contents

CHAPTER 3 VLAN CONFIGURATION

3.1 Managing the Switch....................................................................3-1

3.1.1 Switch Without VLANs ....................................................3-1

3.1.2 Switch with VLANs..........................................................3-2

3.2 Summary of VLAN Local Management........................................3-4

3.2.1 Preparing for VLAN Configuration...................................3-4

3.3 802.1Q VLAN Configuration Menu Screen..................................3-5

3.4 Device VLAN Configuration Screen.............................................3-8

3.4.1 Defining a VLAN............................................................3-10

3.4.2 Changing the VLAN to FID Association ........................3-11

3.4.3 Renaming a VLAN.........................................................3-11

3.4.4 Deleting a VLAN............................................................3-12

3.4.5 Enabling VLANs............................................................3-12

3.4.6 Disabling VLANs ...........................................................3-12

3.4.7 Changing the Forwarding Mode....................................3-13

3.4.8 Paging Through the VLAN List......................................3-13

3.5 Port Assignment Configuration Screen......................................3-14

3.5.1 Changing the Port Mode ...............................................3-15

3.5.2 Assigning a VLAN ID.....................................................3-16

3.5.3 Paging Through the Port List.........................................3-17

3.6 Port Filtering Configuration Screen............................................3-17

3.6.1 Displaying VLAN IDs Associated with a Port ................3-19

3.6.2 Selecting the Type of Filtering for a Port.......................3-20

3.7 VLAN Forwarding Configuration Screen....................................3-21

3.7.1 Viewing Current VLAN Ports.........................................3-22

3.7.2 Paging Through VLAN Forwarding List Entries.............3-23

3.7.3 Adding Forwarding List Entries .....................................3-23

3.7.4 Deleting Forwarding List Entries ...................................3-23

3.7.5 Changing the Frame Format.........................................3-24

3.8 Protocol VLAN Configuration Screen.........................................3-24

3.8.1 Displaying the Current Protocol, VLAN ID, and

Port Assignments..........................................................3-28

3.8.2 Assigning a Protocol Family to a VLAN ID....................3-28

3.8.3 Displaying the Protocol Types on Current Ports ...........3-30

3.9 Protocol Ports Configuration Screen..........................................3-31

3.9.1 Adding/Deleting Ports Associated with a VLAN ID........3-33

3.10 Quick VLAN Walkthrough ..........................................................3-33

iv 802.1Q VLAN User’s Guide

Contents

CHAPTER 4 EXAMPLES

4.1 Example 1, Single Switch Operation...........................................4-1

4.1.1 Solving the Problem........................................................ 4-2

4.1.2 Frame Handling ..............................................................4-3

4.2 Example 2, VLANs Across Multiple Switches..............................4-4

4.2.1 Solving the Problem........................................................ 4-5

4.2.2 Frame Handling ..............................................................4-8

4.3 Example 3, 1D Trunk Connection to 802.1Q VLAN Network....4-10

4.3.1 Solving the Problem...................................................... 4-12

4.3.2 Frame Handling ............................................................4-13

4.4 Example 4, Isolating Network Traffic According to Protocol......4-17

4.4.1 Solving the Problem...................................................... 4-18

802.1Q VLAN User’s Guide v

Contents

vi 802.1Q VLAN User’s Guide

FIGURES

Figure Page

1-1 Example of a VLAN..................................................................1-2

2-1 Inside the Switch...................................................................... 2-4

3-1 Switch Management with Only Default VLAN.......................... 3-1

3-2 Switch Management with VLANs............................................. 3-2

3-3 802.1Q VLAN Screen Hierarchy ..............................................3-4

3-4 802.1Q VLAN Configuration Menu Screen ..............................3-6

3-5 Device VLAN Configuration Screen......................................... 3-8

3-6 Port Assignment Configuration Screen.................................. 3-14

3-7 Port Filtering Configuration Screen........................................ 3-18

3-8 VLAN Forwarding Configuration Screen................................ 3-21

3-9 Protocol VLAN Configuration Screen.....................................3-25

3-10 Protocol Ports Configuration Screen......................................3-31

3-11 Walkthrough Stage One.........................................................3-35

3-12 Walkthrough Stage Two.........................................................3-36

3-13 Walkthrough Stage Three ......................................................3-37

3-14 Walkthrough Stage Four ........................................................3-38

3-15 Final Walkthrough Stage........................................................3-40

4-1 Example 1, Single Switch Operation........................................4-1

4-2 Switch Configured for VLANs...................................................4-2

4-3 Example 2, VLANs Across Multiple Switches ..........................4-5

4-4 Bridge 1 Broadcasts Frames....................................................4-8

4-5 Transmitting to Switch 4...........................................................4-9

4-6 Transmitting to Bridge 4......................................................... 4-10

4-7 Example 3, 1D Trunk Connection to 802.1Q VLAN Network.4-11

4-8 Bridge 1 Broadcasts Frames..................................................4-14

4-9 Switch 2 Forwards to 1Q Trunk..............................................4-15

4-10 Switch 1 Forwards to 1D Trunk..............................................4-15

4-11 Example 4, Isolating Traffic According to Protocol.................4-18

802.1Q VLAN User’s Guide vii

TABLES

Table Page

3-1 802.1Q VLAN Configuration Menu Screen Menu Items ..........3-7

3-2 Device VLAN Configuration Screen Field Definitions .............3-9

3-3 Port Assignment Configuration Screen Field Definitions........3-15

3-4 Port Filtering Configuration Screen Field Definitions .............3-19

3-5 VLAN Forwarding Configuration Screen Field Definitions .....3-22

3-6 Protocol VLAN Configuration Screen Field Definitions .........3-26

3-7 Protocol Ports Configuration Screen Field Definitions ..........3-32

802.1Q VLAN User’s Guide viii

PREFACE

Welcome to the Cabletron Systems 802.1Q VLAN User’s Guide
guide introduces and describes Cabletron Systems’ implementation of the
IEEE 802.1Q standard for 802.1Q Virtual Local Area Network (VLAN)
technology, and the VLAN Local Management screens used to configure
Cabletron Systems products used in 802.1Q VLAN environments.

. This

USING THIS GUIDE

This guide serves as a supplement to the Local Management chapter of
the Cabletron Systems user’s guides for devices that support 802.1Q
VLANs. Read Chapter 1 and Chapter 2 first to gain an understanding of
VLANs, the associated terminology, and the process for configuring
VLANs on a switch. Look at the examples in Chapter 4 to see how
VLANs can be created and changed using the existing network
infrastructure in a building and how the switch handles the frames while
they make their way through the networks shown in the examples.

Chapter 3 describes the VLAN Local Management screens and pro vides a

quick walkthrough on how to use them to configure VLANs in a switch.

STRUCTURE OF THIS GUIDE

This guide is organized as follows:

Chapter 1,

VLANs, including their benefits and uses. This chapter also provides
information about how to obtain additional help if needed.

Virtual Local Area Networks

, presents the basic concepts of

Chapter 2,

VLAN, the steps necessary to prepare an 802.1Q VLAN a ware switch for
VLAN operation, and examines the operation of an 802.1Q VLAN
switch.

Chapter 3,

local and remote management, shows the Local Management screens
used in 802.1Q VLAN configuration and explains their use.

Chapter 4,

how network transmissions are treated by the components of each VLAN.

802.1Q VLAN User’s Guide ix

VLAN Operation

VLAN Configuration

Examples

, offers examples of 802.1Q VLANs and explains

, describes the operation of an 802.1Q

, describes how to set up the switch for

Preface

RELATED DOCUMENTS

Other Cabletron Systems documents that may be useful for understanding
some of the concepts introduced or discussed in this guide are listed
below:

The SmartSwitch user’s guide of any Cabletron Systems 802.1Q VLAN
aware SmartSwitch device.

The manual can be obtained from the World Wide Web in Adobe Acrobat
Portable Document Format (PDF) at the following site:

http://www.cabletron.com/

DOCUMENT CONVENTIONS

The following conventions are used throughout this document:

Note

NOTE

symbol. Calls the reader’s attention to any item of

information that may be of special importance.

In Local Management sections,

Bold type

indicates fields, field values,

and commands that can be highlighted or selected by the user.
In Local Management sections, keystrokes are shown in UPPERCASE.

Italic type

x 802.1Q VLAN User’s Guide

denotes complete book titles.

CHAPTER 1

VIRTUAL LOCAL AREA NETWORKS

This chapter introduces the concepts of Virtual Local Area Networks
(VLANs) and discusses the central concepts of IEEE 802.1Q VLANs.
This chapter also contains information on how to contact Cabletron
Systems for additional support related to VLANs.

1.1 DEFINING VLANs

A Virtual Local Area Network is a group of devices that function as a
single Local Area Netw ork se gment (broadcast domain). The de vices that
make up a particular VLAN may be widely separated, both by geography
and location in the network.

The creation of VLANs allows users located in separate areas or
connected to separate ports to belong to a single VLAN group. Users that
are assigned to such a group will send and receive broadcast and multicast
traffic as though they were all connected to a common network. VLAN
aware switches isolate broadcast, multicast, and unknown traffic received
from VLAN groups, so that traffic from stations in a VLAN are confined
to that VLAN.

When stations are assigned to a VLAN, the performance of their network
connection is not changed. Stations connected to switched ports do not
sacrifice the performance of the dedicated switched link to participate in
the VLAN. As a VLAN is not a physical location, but a membership, the
network switches determine VLAN membership by associating a VLAN
with a particular port or frame type.

Figure 1-1 shows a simple example of a port based VLAN. Tw o b uildings

house the Sales and Finance departments of a single company, and each
building has its own internal network. The stations in each building
connect to a SmartSwitch in the basement. The two SmartSwitches are
connected to one another with a high speed link.

802.1Q VLAN User’s Guide 1-1

Chapter 1:

Virtual Local Area Networks

Building One Building Two

SS

S

FF

A

SmartSwitch SmartSwitch

S

Member of Sales Network

10

9

1

Figure 1-1 Example of a VLAN

trunk

8

F

Member of Finance Network

SSS

FF

7

6

B

2263-01

In this example, the Sales and Finance workstations have been placed on
two separate VLANs. In a plain Ethernet environment, the entire network
is a broadcast domain, and the SmartSwitches follow the IEEE 802.1D
bridging specification to send data between stations. A broadcast or
multicast transmission from a Sales workstation in Building One would
propagate to all the switch ports on SmartSwitch A, cross the high speed
link to SmartSwitch B, and then propagated out all switch ports on
SmartSwitch B. The SmartSwitches treat each port as being equivalent to
any other port, and have no understanding of the departmental
memberships of each workstation.

In a VLAN environment, each SmartSwitch understands that certain
individual ports or frames are members of separate workgroups. In this
environment, a broadcast or multicast data transmission from one of the
Sales stations in Building One would reach SmartSwitch A, be sent to the
ports connected to other local members of the Sales VLAN, cross the high
speed link to SmartSwitch B, and then be sent to any other ports and
workstations on SmartSwitch B that are members of the Sales VLAN.

1-2 802.1Q VLAN User’s Guide

Types of VLANs

1.2 TYPES OF VLANs

There are a number of different strategies for creating Virtual Local Area
Networks, each with their own approaches to defining a station’s
membership in a particular VLAN.

1.2.1 802.1Q VLANs

An 802.1Q VLAN switch determines the VLAN membership of a data
frame by its Tag Header, described later in this chapter. If the frame
received is not tagged, the switch classifies the frame into the VLAN that
is assigned as the default VLAN of the switch.

Some or all ports on the switch may be configured to operate as GARP
VLAN Registration Protocol (GVRP) ports. If a frame received is tagged,
the frame is forwarded to the GVRP ports that are configured to transmit
frames associated with the frame VLAN ID and protocol. If the received
frame is not tagged, the frame is examined and tagged as belonging to the
default VLAN. Then the frame is forwarded to the GVRP ports that are
configured to transmit frames associated with the default VLAN and the
frame protocol.

1.2.2 SecureFast VLANs

Cabletron Systems’ SecureF ast VLAN strategy takes a different approach
to creating virtual LANs. In a SecureFast VLAN environment, the
switches in the network recognize Network Layer routing requests and
translate them. Based on this translation, the switches set up a connection
between the end devices in the network.

1.2.3 Other VLAN Strategies

VLANs may also be created by a variety of addressing schemes,
including the recognition of groups of MAC addresses or types of traffic.
One of the best-known VLAN-like schemes is the use of IP Subnets to
divide networks into smaller subnetworks.

802.1Q VLAN User’s Guide 1-3

Chapter 1:

Virtual Local Area Networks

1.3 BENEFITS AND RESTRICTIONS

The primary benefit of the 802.1Q VLAN technology is that it provides
localization of traffic. This function also offers improvements in security
and performance to stations assigned to a VLAN.

While the localization of traffic to VLANs can improve security and
performance, it imposes some restrictions on network devices that
participate in the VLAN. Through the use of Filtering Database ID’s
(FIDs) security can be implemented to enable or prevent users from one
or more VLANs from communicating with each other.

One or more VLANs can be assigned to a FID so that all the users that
share a common FID can communicate with each other regardless of their
VLAN affiliation. However, for the sake of security, the members of one
FID cannot communicate with the members of another FID.

To set up a VLAN, all the network switch devices that are assigned to the
VLAN must support the IEEE 802.1Q specification for VLANs. Before
you attempt to implement a VLAN strategy, ensure that the switches
under consideration support the IEEE 802.1Q specification.

1.4 VLAN T ERMS

T o fully understand the operation and configuration of port based VLANs,
it is essential to understand the definitions of several key terms.

VLAN ID

A unique number (between 1 and 4094) that identifies a particular VLAN.

VLAN Name

A 32-character alphanumeric name associated with a VLAN ID. The
VLAN Name is intended to make user-defined VLANs easier to identify
and remember.

Filtering Database Identifier (FID)

Addressing information that the device learns about a VLAN is stored in
the filtering database assigned to that VLAN. Several VLANs can be
assigned to the same FID to allow those VLANs to share addressing
information. This enables the devices in the different VLANs to
communicate with each other when the individual ports have been
configured to allow communication to occur.

1-4 802.1Q VLAN User’s Guide

VLAN Terms

The configuration is accomplished using the Local Management VLAN
Forwarding Configuration screen. By default a VLAN is assigned to the
FID that matches its VLAN ID.

Tag Header (VLAN Tag)

Four bytes of data inserted in a frame that identifies the VLAN/frame
classification. The Tag Header is inserted into the frame directly after the
Source MAC address field. Twelve bits of the Tag Header represent the
VLAN ID. The remaining bits are other control information.

Tagged Frame

A data frame that contains a Tag Header. A VLAN aware device can add
the Tag Header to any frame it transmits.

Untagged Frame

A data frame that does not have a Tag Header.

Default VLAN

The VLAN to which all ports are assigned upon initialization. The
Default VLAN has a VLAN ID of 1 and cannot be deleted or renamed.

Forwarding List

A list of the ports on a particular device that are eligible to transmit
frames for a selected VLAN.

Port VLAN List

A per port list of all eligible VLANs whose frames can be forwarded out
one specific port and the frame format (tagged or untagged) of
transmissions for that port. The Port VLAN List specifies what VLANs
are associated with a single port for frame transmission purposes.

Filtering Database

A database structure within the switch that keeps track of the associations
between MAC addresses, VLANs, and interface (port) numbers. The
Filtering Database is referred to when a switch makes a forwarding
decision on a frame.

1Q T runk

A connection between 802.1Q switches that passes only traffic with a
VLAN Tag Header inserted in the frame. By default, a port designated as
a 1Q Trunk port has all VLANs in its Port VLAN List and is configured to
transmit all frames as tagged frames. A 1Q Trunk drops all incoming
frames that do not have a VLAN tag.

802.1Q VLAN User’s Guide 1-5

Chapter 1:

1D T runk

Virtual Local Area Networks

A connection from a switch that passes only untagged traffic. By default,
a port designated as a 1D Trunk port has all VLANs on its Port VLAN
List and is configured to transmit all frames as untagged frames.

Generic Attribute Registration Protocol (GARP)

GARP is a protocol used to propagate state information throughout a
switched network.

GARP VLAN Registration Protocol (GVRP)

A GARP application used to dynamically create VLANs across a
switched network.

GARP Multicast Registration Protocol (GMRP)

A GARP application that functions in a similar fashion as GVRP, except
that GMRP registers multicast addresses on ports to control the flooding
of multicast frames.

1-6 802.1Q VLAN User’s Guide

Getting Help

1.5 GETTING HELP

For additional support related to this device or document, contact
Cabletron Systems using one of the following methods:

World Wide Web http://www.cab letron.com/
Phone [phone]
Internet mail [e-mail]
FTP ftp://ftp.cabletron.com/

Login
Password

To send comments or suggestions concerning this document, contact the
Cabletron Systems Technical Writing Department via the following
email address:

Make sure to include the document Part Number in the email message.

[e-mail]

Before calling Cabletron Systems, have the following information
ready:

•

Your Cabletron Systems service contract number

•

A description of the failure

anonymous
your email address

•

A description of any action(s) already taken to resolve the problem
(e.g., changing mode switches, rebooting the unit, etc.)

•

The serial and revision numbers of all involved Cabletron Systems
products in the network

•

A description of your network environment (layout, cable type, etc.)

•

Network load and frame size at the time of trouble (if known)

•

The device history (i.e., have you returned the device before, is this a
recurring problem, etc.)

•

Any previous Return Material Authorization (RMA) numbers

802.1Q VLAN User’s Guide 1-7

Chapter 1:

Virtual Local Area Networks

1-8 802.1Q VLAN User’s Guide

CHAPTER 2

VLAN OPERATION

This chapter describes the operation of a VLAN switch and discusses the
operations that a VLAN switch performs in response to both normal and
VLAN-originated network traffic.

2.1 DESCRIPTION

The 802.1Q VLAN operation is slightly different than the operation of
traditional switched networking systems. These differences are due to the
importance of keeping track of each frame and its VLAN association as it
passes from switch to switch or from port to port within a switch.

2.2 VLAN COMPONENTS

Before describing the operation of an 802.1Q VLAN, it is important to
understand the basic elements that are combined to make up an 802.1Q
VLAN.

Stations

A station is any end unit that belongs to a network. In the vast majority of
cases, stations are the computers through which the users access the
network.

Switches

In order to configure a group of stations into a VLAN, the stations must
be connected to VLAN aware switches. It is the job of the switch to
classify received frames into VLAN memberships and transmit frames,
according to VLAN membership, with or without a VLAN Tag Header.

802.1Q VLAN User’s Guide 2-1

Chapter 2:

VLAN Operation

2.3 CONFIGURATION PROCESS

Before a VLAN can operate, steps must be performed to configure the
switch to establish and configure a VLAN. Cabletron Systems VLAN
aware SmartSwitches default to operate in the 802.1Q VLAN mode.
However, further configuration is necessary to establish multiple logical
networks.

NOTE

The actual steps involved in VLAN configuration using Local
Management are presented in Chapter 3,

Configuration

must be taken in very general terms, and is intended only to aid
in the Administrator’s understanding of VLAN switch operation.

.This brief section describes the actions that

VLAN

2.3.1 Defining a VLAN

A VLAN must exist and have a unique identity before any ports or rules
can be assigned to it. The Administrator defines a VLAN by assigning it a
unique identification number (the VLAN ID), a filter database
association, and an optional name. The VLAN ID is the number that will
identify data frames originating from, and intended for, the ports that will
belong to this new VLAN.

2.3.2 Classifying Frames to a VLAN

Now that a VLAN has been created, rules are defined to classify all
frames in a VLAN. This is accomplished through management by
associating a VLAN ID with each port on the switch. Optionally, frames
can be classified according to a protocol identifier contained within the
frame. The order of frame classification priority is by VLAN Tag, a
protocol match, and lastly the PVID. This combination of the switch
port’s identification and the VLAN ID becomes the Port VLAN ID
(PVID).

At the same time, the Administrator configures the trunk ports that need to
consider themselves members of every VLAN. The configuration of trunk
ports is very important in multiswitch VLAN configurations where a
frame’s VLAN membership needs to be maintained across several
switches.

2-2 802.1Q VLAN User’s Guide

VLAN Switch Operation

2.3.3 Customizing the VLAN Forwarding List

Each port on a VLAN aware switch has a VLAN forwarding list that
contains, as a minimum, the PVID of the VLAN configured. Additionally,
the Port VLAN Forwarding List of each port can be configured to allow
any number of VLANs to be added to its list. In the case of GMRP
(dynamic VLANs), the list can have VLANs added and deleted by the
switch as directed by the protocol.

2.4 VLAN SWITCH OPERATION

IEEE 802.1Q VLAN switches act on the classification of frames into
VLANs. Sometimes, VLAN classification is based on tags in the headers
of data frames. These VLAN tags are added to data frames by the switch
as the frames are transmitted out certain ports, and are later used to make
forwarding decisions by the switch and other VLAN aware switches. In
the absence of a VLAN tag header, the classification of a frame into a
particular VLAN depends upon the configuration of the switch port that
received the frame.

The operation of an 802.1Q VLAN switch is best understood from a point
of view of the switch itself. To illustrate this concept, the examples that
follow view the switch operations from

inside

the switch.

802.1Q VLAN User’s Guide 2-3

Chapter 2:

VLAN Operation

Figure 2-1 depicts the inside of a switch with six ports, numbered one

through six. The switch has been configured to associate VLAN A and B
with FID 2, VLAN C and D with FID 3, and VLAN E with FID 4. Port 6
has been classified as a 1Q Trunk Port. This classification establishes that
all VLANs are members of the Port VLAN List for Port 6 and the frames
transmitted for all VLANs will contain a tag header. Also the PVID for
Port 6 is set to the default VLAN with its corresponding relationship to
FID 1. Although untagged frames are not usually present on a 1Q Trunk
Port, any untagged frames received w ould need to be classified if the port
has not been configured to drop all untagged frames.

Port 1

Port 2

A
FID 2

D
FID 3

Port 4

Figure 2-1 Inside the Switch

Port 5

B
FID 2

E
FID 4

Port 3

C
FID 3

Default
FID 1

Port 6

2599-02

2.4.1 Receiving Frames from VLAN Ports

When a switch is placed in 802.1Q Operational Mode, every frame
received by the switch must belong, or be assigned, to a VLAN.

Untagged Frames

The switch receives a frame from Port 1 and examines the frame. The
switch notices that this frame does not currently have a VLAN tag. The
switch recognizes that Port 1 is a member of VLAN A and classifies the
frame as such. In this fashion, all untagged frames entering a VLAN
switch assume membership in a VLAN.

NOTE

2-4 802.1Q VLAN User’s Guide

A VLAN ID is always assigned to a port. By default, it is the
Default VLAN (VLAN ID = 1).

VLAN Switch Operation

The switch will now make a forwarding decision on the frame, as
described in Section 2.4.2, Forwarding Decisions.

Tagged Frames

In this example, the switch receives a tagged frame from Port 4. The
switch examines the frame and notices the frame is tagged for VLAN C.
This frame may have already been through a VLAN aware switch, or
originated from a station capable of specifying a VLAN membership. If a
switch receives a frame containing a tag, the switch will classify the frame
in regard to its tag rather than the PVID for its port.

The switch will now make a forwarding decision on the frame, as
described in Section 2.4.2, Forwarding Decisions.

2.4.2 Forwarding Decisions

The type of frame under consideration and the filter setting of a VLAN
switch determines how it forwards VLAN frames.

2.4.2.1 Broadcasts, Multicasts, and Unknown Unicasts

If a frame with a broadcast, multicast, or other unknown address is
received by an 802.1Q VLAN aware switch, the switch checks the VLAN
classification of the frame. The switch then forwards the frame out all
ports that are identified in the Forwarding List for that VLAN. For
example, if Port 3, shown in Figure 2-1, received the frame, the frame
would then be sent to all ports that had VLAN C in their Port VLAN List.

2.4.2.2 Known Unicasts

When a VLAN switch receives a frame with a known MAC address as its
destination address, the action taken by the switch to determine how the
frame is transmitted depends on the VLAN, the VLAN associated FID,
and if the port identified to send the frame is enabled to do so.

When a frame is received it is classified into a VLAN. The destination
address is looked up in the FID associated with the VLAN. If a match is
found, it is forwarded out the port identified in the lookup if, and only if,
that port is allowed to transmit frames for that VLAN. If a match is not
found, then the frame is flooded out all ports that are allowed to transmit
frames belonging to that VLAN.

802.1Q VLAN User’s Guide 2-5

Chapter 2: VLAN Operation

For example, assume that a frame is received by the switch depicted in

Figure 2-1. This frame is a unicast untagged frame received on Port 3.

The frame is then classified for VLAN C. The switch then makes its
forwarding decision by comparing the destination MAC address to its
filtering database. In this case, the MAC address is looked up in the
filtering database FID 3, which is associated with VLAN C and VLAN D.
The switch recognizes the destination MAC address of the frame as being
located out Port 4.

Having made the forwarding decision, the switch now examines the Port
VLAN List of Port 4 to determine if it may transmit a frame belonging to
VLAN C. If so, the frame is transmitted out Port 4. If Port 4 has not been
configured to transmit frames belonging to VLAN C, the frame is
discarded.

2.5 GARP SWITCH OPERATION

Some or all ports on the switch may be activated to operate under the
Generic Attribute Registration Protocol (GARP) applications, GVRP
and/or GMRP. For a description of the protocols and how the frames are
handled, refer to the user’s guide of your SmartSwitch device.

2-6 802.1Q VLAN User’s Guide

CHAPTER 3

VLAN CONFIGURATION

This chapter describes how to set up the switch for local or remote
management, and the VLAN Local Management screens used to create
and configure VLANs in a SmartSwitch.

3.1 MANAGING THE SWITCH

The switch may be managed locally via a terminal connected to the COM
port, or remotely (SNMP or Telnet sessions) from a management station
connected to a switch port that is a member of the same VLAN as the
switch’s Host Data Port. (By def ault, this is the default VLAN.) When the
switch is configured with VLANs, special precautions must be taken to
use remote management.

3.1.1 Switch Without VLANs

When the switch is powered up, the switch uses its default settings to
switch frames like an 802.1D switch. In this default configuration, all
ports are a member of the default VLAN (VLAN 1) including the virtual
Host Data Port of the switch, so any port can be used to manage the
device as shown in Figure 3-1.

802.1Q Switch

1
2

Host
Data
Port

4
5

3 6

NOTE: All ports, including the virtual Host Data Port, are
members of the default VLAN. Therefore, any station
shown may be used as the management station.

2599_14

Figure 3-1 Switch Management with Only Default VLAN

802.1Q VLAN User’s Guide 3-1

Chapter 3: VLAN Configuration

3.1.2 Switch with VLANs

If the switch is to be configured for multiple VLANs, it may be desirable
to configure a management-only VLAN. This allows a management
station connected to the management VLAN to manage all ports on the
switch and make management secure by preventing management via
ports assigned to other VLANs.

NOTE

The switch’s virtual Host Data Port, like any other port, has
configurable VLAN membership. For manageability of the
device to be maintained, this port must be a member of the
same VLAN as the port to which the management station is
connected.

Figure 3-2 shows an example of a switch configured with port 1 on the

Management VLAN port and the other users belonging to VLANs A, B,
and C.

Management
VLAN

VLAN A

VLAN A

802.1Q Switch

1
2

Host
Data
Port

4
5

3 6

VLAN B

VLAN B

VLAN C

7

Set as an 802.1Q Trunk port.

Figure 3-2 Switch Management with VLANs

25992_15

To set up the switch shown in Figure 3-2 to establish a management
VLAN on port 1, use the process described below:

1. Use the Device VLAN Configuration screen for the following:
a. Define a new VLAN named “Management VLAN” (or other

suitable name) and its VLAN ID. In this example, the VLAN ID is
set to 2.

3-2 802.1Q VLAN User’s Guide

Managing the Switch

b. Set the FID so the Management VLAN has its own number to

make the VLAN secure. In this example, the FID is 3 and no other
VLAN should be assigned to this FID. This keeps the new VLAN
from sharing its filtering database with other VLANs in the
switch. For details on defining a VLAN, refer to Section 3.4.1.

2. Use the Port Assignment Configuration screen for the following:

a. Assign the VLAN ID, 2, of the ne w Management VLAN to a port.

In this example, it is port 1. Leave the Port Mode setting in the
default value of HYBRID.

NOTE

It is not necessary to configure a physical port for management
on each switch. Only those switches that will have a
management station attached to it need a physical port
assigned to the Management VLAN.

b. Assign the VLAN ID, 2, of the new Management VLAN to the

Host Data Port. The port number will depend on the device. This
port is not a physical port and will usually be one number above
the maximum number physical ports on the device, including the
ports on any optional interfaces installed. In this example, it will
be port 8. Leave the Port Mode setting in the default value of
HYBRID. For details on assigning a VLAN ID, refer to

Section 3.4.2.

This process would be repeated on every switch that is connected in the
network to ensure that each switch has a secure Management VLAN for
switch management.

If the switch was connected to another switch via port 7, which was set as
a 1Q Trunk port, then the management station connected to the
Management VLAN port of either switch could manage both switches.

NOTE

The management stations at each switch must be on the same
Management VLAN.

No matter how many switches are connected, a management station
connected to any port on the same Management VLAN can be used to
remotely manage any Cabletron Systems 802.1Q switch in the network as
long as the Host Data Port of all the switches are members of the same
Management VLAN.

802.1Q VLAN User’s Guide 3-3

Chapter 3: VLAN Configuration

3.2 SUMMARY OF VLAN LOCAL MANAGEMENT

The VLAN configuration process is an extension of normal Local
Management operations. A series of Local Management screens provides
access to the functions and commands necessary to add, change, or delete
VLANs and to assign ports to those VLANs.

A switch supporting 802.1Q VLANs provides the VLAN Configuration
screens as a standard part of its Local Management hierarchy when the
switch is configured to operate in 802.1Q Mode. The hierarchy of the
Local Management screens pertaining to 802.1Q VLAN configuration is
shown in Figure 3-3.

802.1Q VLAN
Configuration Menu

Figure 3-3 802.1Q VLAN Screen Hierarchy

Device VLAN Configuration
Port Assignment Configuration
Port Filtering Configuration

VLAN Forwarding Configuration
Protocol VLAN Configuration

Protocol Ports Configuration

25994_03

3.2.1 Preparing for VLAN Configuration

A little forethought and planning is essential to a good VLAN
implementation. Before attempting to configure a single switch for VLAN
operation, consider the following:

• How many VLANs will be required

• What stations will belong to them

• What ports are connected to those stations

• What ports will be configured as GARP-aware ports

It may also be helpful to sketch out a diagram of your VLAN strategy.
The examples provided in Chapter 4 may be useful for a depiction of the
planning process.

Access Local Management as described in your device user’s guide.
Perform all required initial setup operations. Navigate to the 802.1Q
VLAN Configuration Menu screen to begin the VLAN configuration
process for the device.

3-4 802.1Q VLAN User’s Guide

802.1Q VLAN Configuration Menu Screen

3.3 802.1Q VLAN CONFIGURATION MENU SCREEN

When to Use

To select screens to assign switched network ports to VLANs, define new
VLANs, and configure port filtering according to a VLAN list or
untagged frames. Network users can be logically grouped into VLANs
even if they span long physical distances over a vast, intricate physical
network. The VLAN Local Management menu items listed on the 802.1Q
VLAN Configuration Menu allow such VLANs to be configured on a
network at the switched port of the device or SmartSwitch chassis. Also,
some or all of the ports on the switch can be configured as GVRP ports,
which enable frames received with a particular VLAN ID and protocol to
be transmitted on a limited number of ports. This keeps the traffic
associated with a particular VLAN and protocol to be isolated from the
other parts of the network.

Before attempting the VLAN configuration, ensure that the device to be
configured has been set for 802.1Q SWITCHING mode. The mode
selection is a Local Management operation that is accessible through the
General Configuration screen of the device.

The device resets when changing operational modes.

!

CAUTION

802.1Q VLAN User’s Guide 3-5

Chapter 3: VLAN Configuration

How to Access

Use the arrow keys to highlight the 802.1Q VLAN CONFIGURA TION
MENU item from the module, device, or chassis specific Configuration

Menu screen and press ENTER. The 802.1Q VLAN Configuration Menu
screen displays.

Screen Example

6C105 LOCAL MANAGEMENT

802.1Q VLAN Configuration Menu

Module Type: xxxxx-xx
Slot Number: xx

DEVICE VLAN CONFIGURATION

PORT ASSIGNMENT CONFIGURATION
PORT FILTERING CONFIGURATION
VLAN FORWARDING CONFIGURATION
PROTOCOL VLAN CONFIGURATION

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

EXIT

RETURN

25994-04

Figure 3-4 802.1Q VLAN Configuration Menu Screen

3-6 802.1Q VLAN User’s Guide

802.1Q VLAN Configuration Menu Screen

Menu Definitions

Table 3-1 802.1Q VLAN Configuration Menu Screen Menu Items
Menu Item Screen Function

DEVICE VLAN
CONFIGURATION

PORT
ASSIGNMENT
CONFIGURATION

PORT FILTERING
CONFIGURATION

VLAN
FORWARDING
CONFIGURATION

PROTOCOL
VLAN
CONFIGURATION

Used to view, add, name, enable, or disable VLANs
within the device, and also associate the VLANs to a
Filter Database ID (FID). It also enables the user to
configure attributes that apply to the entire switch and/or
VLANs. Refer to Section 3.4 for additional information.

Displays a list of ports and enables the user to assign a
Port VLAN ID (PVID) to each port. The screen also allows
the user to change the operational mode of a port. Refer
to Section 3.5 for additional information.

Used to set the switch to filter out inbound frames to
prevent them from being forwarded by the switch out a
particular port. This screen also lists the VLANs whose
frames are eligible to be transmitted out that port. Refer
to Section 3.6 for additional information.

Used to view which ports are included in the VLAN’s
Forwarding List and whether to include a Tag Header in a
frame being transmitted. Refer to Section 3.7 for
additional information.

Used to assign VLAN IDs to protocol types of received
frames and to access the Protocol Port Configuration
screen to add or delete transmitting ports associated with
a specific VLAN ID and protocol type. Refer to

Section 3.6 for additional information.

802.1Q VLAN User’s Guide 3-7

Chapter 3: VLAN Configuration

3.4 DEVICE VLAN CONFIGURATION SCREEN

When to Use

To define the operating characteristics of the switch to add, name, delete,
enable, and disable VLANs, and assign VLANs to FIDs. The screen can
display up to eight VLANs simultaneously.

How to Access

Use the arrow keys to highlight the DEVICE VLAN
CONFIGURA TION menu item on the 802.1Q VLAN Configuration

Menu screen and press ENTER. The Device VLAN Configuration screen
displays.

Screen Example

6C105 LOCAL MANAGEMENT

Device VLAN Configuration

Module Type: xxxxx-xx
Slot Number: xx

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

Forward Default VLAN Out All Ports: [NO]

VLAN ID
1

VLAN ID: 1 FID: 1 VLAN Name: DEFAULT VLAN [ADD]

SAVE

FID
1

VLAN Name
DEFAULT VLAN

EXIT

Admin Status

[Enabled]

RETURN

25993-05

Figure 3-5 Device VLAN Configuration Screen

3-8 802.1Q VLAN User’s Guide

Device VLAN Configuration Screen

Field Definitions

Table 3-2 Device VLAN Configuration Screen Field Definitions
Use this field … To …

Forward Default
VLAN Out All
Ports
(Toggle)

VLAN ID -

part of screen

(Read-Only)

FID -

upper

upper part

of screen

(Read-Only)

Admin Status

(Toggle)

VLAN ID -

lower

part of screen

(Modifiable)

lower part

FID -

of screen

(Modifiable)

Assign or remove the default VLAN from the Port VLAN
List for all ports. When set to YES, the default VLAN is
added to the Port VLAN List of all ports that do not already
include it. When set to NO, the default VLAN is removed
from the Port VLAN List of an y port that does not have the
default VLAN as its PVID. The default is NO.

Display the assigned VLAN IDs that are configured in the
module. Initially, only the Default VLAN (VLAN ID: 1) is
listed.

Display the names assigned to the corresponding VLAN
IDs. If a name has not been assigned to a VLAN, the
VLAN Name field displays, “Not Defined”.

Set the current state of the associated VLAN. This field
toggles between Enabled and Disabled. An enab led VLAN
is operational and a disabled VLAN is not operational. If a
VLAN is disabled, all ports assigned to that VLAN will
assume a PVID of the default VLAN.

Enter input to select or define a new VLAN ID.

Display the FID currently associated with the VLAN typed
in the VLAN ID field. A new number can be typed into the
FID field to reassign the VLAN to a different filtering
database. Each VLAN will def ault to a FID that matches its
VLAN ID and can be changed to a FID from 1 to 1094.

VLAN Name -

lower part of
screen

(Modifiable)

ADD/DEL

(Toggle)

Assign or change names of VLANs. The VLAN Name
(with up to 32 characters) is an optional attribute of a
VLAN, and is not required for VLAN operation.

T oggle the action tak en between adding the entered VLAN
to the switch or deleting the selected VLAN from the
switch.

802.1Q VLAN User’s Guide 3-9

Chapter 3: VLAN Configuration

3.4.1 Defining a VLAN

To define a VLAN, proceed as follows:

1. Use the arrow keys to highlight the VLAN ID field.

2. Enter the VLAN ID using a unique number between 2 and 4094. The

VLAN IDs of 0, 1, and 4095 may not be used for user-defined VLANs.
If an illegal number is entered, the Event Message Line will display:

”PERMISSIBLE RANGE FOR VLAN IDS: 2 to 4094” and the field
will refresh with the previous value.

NOTE

Each VLAN ID must be unique. If a duplicate VLAN ID is

entered, the switch assumes that the Administrator intends to

modify the existing VLAN.

3. If the VLAN is to be assigned to a different filtering database, use the

arrow keys to highlight the FID field. If the VLAN is not going to be
assigned to a different FID, go to step 5.

4. Type in the ID number of the FID.

5. Use the arrow keys to highlight the VLAN Name field.

6. Type a name of up to 32 ASCII characters in the VLAN Name field

This is an optional attribute of a VLAN, and is not required for VLAN
operation.

7. Use the arrow keys to highlight the ADD/DEL field.

8. Press the SPACE bar to select ADD for a defined VLAN. Press

ENTER. The new VLAN will be added to the VLAN list. The message
“VLAN ADDED” displays in the Event Message Line in the upper
left-hand corner of the screen.

The VLAN will not be saved to the switch until the configuration is
saved.

.

9. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The message “SAVED OK” displays.

3-10 802.1Q VLAN User’s Guide

Device VLAN Configuration Screen

3.4.2 Changing the VLAN to FID Association

To change the association of a VLAN to a FID, proceed as follows:

1. Use the arrow keys to highlight the VLAN ID field.

2. Enter the VLAN ID of the VLAN of which the FID association is to

be changed.
If an illegal number is entered, the Event Message Line will display:

”PERMISSIBLE RANGE FOR VLAN IDS: 2 to 4094” and the field
will refresh with the previous value.

3. Use the arrow keys to highlight the FID field.

4. Type in the ID number of the FID. If the ID number is valid, the Event

Message Line in the upper left hand corner of the screen displays
“VLAN # UPDATED”, where # represents the entered ID number.

5. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The message “SAVED OK” displays.

3.4.3 Renaming a VLAN

To change the name of an existing VLAN, proceed as follows:

1. Enter the VLAN ID. The VLAN Name field will automatically update

to display the VLAN’s current name.

2. Use the arrow keys to highlight the VLAN Name field.

3. Type a name of up to 32 ASCII characters in the VLAN Name field.

Press ENTER. If the name is valid, the Event Message Line in the
upper left hand corner of the screen displays “VLAN # UPDATED”,
where # represents the entered VLAN name.

4. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The message “SAVED OK” displays.

802.1Q VLAN User’s Guide 3-11

Chapter 3: VLAN Configuration

3.4.4 Deleting a VLAN

To delete a VLAN from the current VLAN list, proceed as follows:

1. Enter the VLAN ID. The VLAN Name field will automatically update

to display the VLAN’s name if that VLAN has been previously
configured.

2. Use the arrow keys to highlight the ADD/DEL field.

3. Press the SPACE bar to select DEL. Press ENTER. The VLAN is

removed from the list. The message “VLAN DELETED” displays in
the Event Message Line in the upper left-hand corner of the screen.

4. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The message “SAVED OK” displays.

NOTE

The default VLAN cannot be deleted from the list.

3.4.5 Enabling VLANs

To enable a VLAN, proceed as follows:

1. Use the arrow keys to highlight the Admin Status field of the selected

VLAN.

2. Press the SPACE bar to toggle the field to display Enabled.

3. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

4. Press ENTER. The message “SAVED OK” displays.

3.4.6 Disabling VLANs

To disable a VLAN, proceed as follows:

1. Use the arrow keys to highlight the Admin Status field of the selected

VLAN.

2. Press the SPACE bar to toggle the field to display Disabled.

3. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

3-12 802.1Q VLAN User’s Guide

Device VLAN Configuration Screen

4. Press ENTER. The message “SAVED OK” displays.

NOTE

The default VLAN cannot be disabled.

3.4.7 Changing the Forwarding Mode

To change the forwarding mode of the switch, proceed as follows:

1. Use the arrow keys to highlight the Forward Default VLAN Out All

Ports field.

2. Press the SPACE bar or BACKSPACE to toggle between YES and

NO. The YES selection places the default VLAN (VLAN ID=1) in the

Port VLAN Lists of all ports on the switch. The NO selection removes
the default VLAN from the Port VLAN Lists of all ports, unless those
ports have a PVID of 1 (those belonging to only the Default VLAN).

3. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

4. Press ENTER. The message “SAVED OK” displays.

3.4.8 Paging Through the VLAN List

To display additional VLANs that do not display in the current VLAN
List as shown on the screen, use the NEXT or PREVIOUS commands
located at the bottom of the screen, as follows:

NOTE

The NEXT and PREVIOUS fields will only display if there are
further VLAN List entries to page through.

1. To display the next screen, use the arrow keys to highlight NEXT.

Press ENTER to view the entries on the next screen.

2. To display the previous screen, use the arrow keys to highlight

PREVIOUS. Press ENTER to view the entries on the previous screen.

802.1Q VLAN User’s Guide 3-13

Chapter 3: VLAN Configuration

3.5 PORT ASSIGNMENT CONFIGURATION SCREEN

When to Use

To select a mode of operation for each port and to assign a Port VLAN
Identification (PVID) to each port.

How to Access

Use the arrow keys to highlight the POR T ASSIGNMENT
CONFIGURA TION menu item on the 802.1Q VLAN Configuration

Menu screen and press ENTER. The Port Assignment Configuration
screen displays.

Screen Example

6C105 LOCAL MANAGEMENT

Port Assignment Configuration

Module Type: xxxxx-xx
Slot Number: xx

Port

1
2
3
4
5
6
7
8
9
10
11
12

Port Mode

[1D TRUNK]
[1Q TRUNK]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]

VLAN ID

[0001]

[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]

FID

0001
0001
0001
0001
0001
0001
0001
0001
0001
0001
0001
0001

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

VLAN Name

Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN

SAVE PREVIOUS NEXT

EXIT

RETURN

25992-06

Figure 3-6 Port Assignment Configuration Screen

3-14 802.1Q VLAN User’s Guide

Port Assignment Configuration Screen

Field Definitions

Table 3-3 Port Assignment Configuration Screen Field Definitions

Use this field … To …

Port

(Read-Only)

Port Mode

(Selectable)

VLAN ID

(Selectable)

FID (Read-Only) Display the FID associated with the VLAN ID. This field

VLAN Name

(Read-Only)

See the port numbers of the interfaces of the current
module.

Display the current operational mode for the
corresponding port and select one of three modes:
HYBRID, 1Q TRUNK, or ID TRUNK. The default is
HYBRID.

Select the ID number of the VLAN that is associated with
the current port (Port VLAN ID). This is the VLAN ID into
which any untagged frame will be classified. The default
PVID is 0001.

updates as the associated VLAN ID field is changed.
Display the name that is associated with the current

VLAN ID. If a name was not assigned to a VLAN, “NOT
DEFINED” displays as the VLAN name.

3.5.1 Changing the Port Mode

To change the operational mode of a port, proceed as follows.

1. Use the arrow keys to highlight the PORT MODE field for the

module and port combination you wish to change.

2. Use the SPACE bar or BACKSPACE key to step through the available

selections. A port may be configured for any of the following modes:

• HYBRID – This is the default mode for all ports on the switch.

The initial Port VLAN List includes the PVID with a frame format
of untagged. Any other VLANs desired for the Port VLAN List
need to be manually configured. By changing the default mode to
1Q Trunk or 1D Trunk, the Port VLAN List and the associated
frame type are automatically configured.

802.1Q VLAN User’s Guide 3-15

Chapter 3: VLAN Configuration

• 1Q TRUNK – This mode sets the port for transmitting to another

802.1Q aware device. In this mode, all frames are transmitted with
a tag header included in the frame (excluding BPDUs). The switch
will drop all untagged frames it receives on the 1Q T runk port. The
Port VLAN List for the port includes all VLANs.

• 1D TRUNK – This mode sets the port for transmitting to a legacy

802.1D switch fabric. In this mode, all incoming frames are
classified into the default VLAN and all frames are transmitted
untagged. The switch expects to receive only untagged frames
through the 1D Trunk port. This mode also updates the Port
VLAN List and makes the port eligible to transmit frames for all
VLANs. The 1D T runk mode can be used in conjunction with the
“Forward Default VLAN Out All Ports” parameter and the Default
VLAN to allow all stations on a legacy portion of the network to
access all stations or servers in the 802.1Q portion of the network.

3. When the desired operational mode for the port is displayed, use the

arrow keys to highlight the SAVE command at the bottom of the
screen.

4. Press ENTER. The message “SAVED OK” displays.

3.5.2 Assigning a VLAN ID

The Port Assignment Configuration screen also enables the user to set
each port’s VLAN ID (PVID) by stepping through a list of all configured
VLANs. To assign a VLAN ID to a port in this manner, perform the
following steps:

NOTE

1. Use the arrow keys to highlight the VLAN ID field for the port

2. Use the SPACE bar or BACKSPACE key to step sequentially through

3-16 802.1Q VLAN User’s Guide

It may be necessary to use the NEXT and PREVIOUS
commands to page through the available ports. For
instructions, refer to Section 3.5.3.

combination you wish to change.

the previously configured VLAN ID numbers. Only existing VLAN
IDs will be displayed.

Port Filtering Configuration Screen

NOTE

New VLAN IDs must be created with the functions available on
the Device VLAN Configuration screen, discussed in

Section 3.4.

3. When the desired VLAN ID is displayed, use the arrow keys to

highlight the SAVE command at the bottom of the screen.

4. Press ENTER. The message “SAVED OK” displays.

3.5.3 Paging Through the Port List

To display additional ports that do not display in the current screen, use
the NEXT or PREVIOUS commands at the bottom of the screen, as
follows:

NOTE

1. To display the next screen, use the arrow keys to highlight NEXT.

2. To display the previous screen, use the arrow keys to highlight

The NEXT and PREVIOUS fields will only display if there are
further Port List entries to page through.

Press ENTER to view the entries on the next screen.

PREVIOUS. Press ENTER to view the entries on the previous screen.

3.6 PORT FILTERING CONFIGURATION SCREEN

When to Use

To perform the following functions:

• Select a port and view a list of VLANs that are configured to ha ve their

frames transmitted out that port.

• Filter out certain incoming frames according to the VLAN List and

prevent them from being switched and transmitted out another port.

• Filter out of all incoming untagged frames so they will not be

transmitted out another port.

802.1Q VLAN User’s Guide 3-17

Chapter 3: VLAN Configuration

How to Access

Use the arrow keys to highlight the PORT FILTERING
CONFIGURATION menu item on the 802.1Q VLAN Configuration

Menu screen and press ENTER. The Port Filtering Configuration screen
displays.

Screen Example

6C105 LOCAL MANAGEMENT

Port Filtering Configuration

Module Type: xxxxx-xx
Slot Number: xx

Port VLAN List

VLAN ID
0001
0003
0004
0012
0014
0020

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

VLAN Name
Default VLAN
Not Defined
Not Defined
Not Defined
Not Defined
Not Defined

Port: [002]

SAVE PREVIOUS NEXT

Filter Using VLAN Lists: [NO]

Filter All Untagged Frames: [NO]

EXIT

RETURN

25992-07

Figure 3-7 Port Filtering Configuration Screen

3-18 802.1Q VLAN User’s Guide

Port Filtering Configuration Screen

Field Definitions

Table 3-4 Port Filtering Configuration Screen Field Definitions
Use this field … To …

VLAN ID

(Read-Only)

VLAN Name

(Read-Only)

Port

(Selectable)

Filter Using
VLAN Lists

(Toggle)

Filter All
Untagged
Frames

(Toggle)

See the VLAN ID of the VLANs that are configured to ha ve
their frames transmitted out the port selected in the Port #
field.

See the names of the VLANs associated with the VLAN
ID. If a VLAN does not have a name, “Not Defined” is
displayed.

To step to the port number of the interface being
configured including the selection of ALL ports.

Filter out (drop) frames that are classified, via their VLAN
tag, as belonging to a VLAN that is not on the Port VLAN
List and prevent them from being forwarded by the switch.

This field toggles between YES and NO. YES enables
filtering according to the Port VLAN List. NO allows the
switch to forward the frames. The default is NO.

To filter out all incoming untagged frames so they will not
be forwarded by the switch. This field toggles between
YES and NO. YES enables the filtering of untagged
frames. NO allows the switch to forward untagged frames.
The default is NO.

3.6.1 Displaying VLAN IDs Associated with a Port

To display the VLAN IDs and VLAN Names of the VLANs associated
with a particular port, proceed as follows:

1. Use the arrow keys to highlight the Port field.

2. Use the SPACE bar or BACKSPACE key to step through the available

port selections. The screen displays the Port VLAN List of the selected
Port. If ALL is selected, no VLAN ID or VLAN Name information is
displayed under Port VLAN List.

3. T o display additional VLANs that do not display in the current screen

display, use the NEXT or PREVIOUS commands located at the
bottom of the screen, as follows:

802.1Q VLAN User’s Guide 3-19

Chapter 3: VLAN Configuration

NOTE

The NEXT and PREVIOUS fields will only display if there are

further VLANs in the list to page through.

4. To display the next screen, use the arrow keys to highlight NEXT.

Press ENTER to view the entries on the next screen.

5. To display the previous screen, use the arrow keys to highlight

PREVIOUS. Press ENTER to view the entries on the previous screen.

3.6.2 Selecting the Type of Filtering for a Port

A port can be set to filter out received frames according to its Port VLAN
List. This keeps them from being transmitted and drops all untagged
frames from being transmitted. To set this type of filtering, proceed as
follows:

1. Use the arrow keys to highlight the Port # field.

2. Use the SPACE bar or BACKSPACE key to step through the available

port selections.

3. Use the arrow keys to highlight the Filter Using VLAN List field.

4. Use the SPACE bar or BACKSPACE key to toggle between YES and

NO. When set to YES, the switch will drop all incoming frames that

are classified with a VLAN tag of a VLAN that does not appear on the
Port VLAN List. The default is NO.

5. Use the arrow keys to highlight the Filter All Untagged Frames field.

6. Use the SPACE bar or BACKSPACE key to toggle between YES or

NO. When set to YES, the switch will drop all incoming frames that

do not have a VLAN tag header. The default is NO.

7. To save the settings, Use the arrow keys to highlight the SAVE

command at the bottom of the screen.

8. Press ENTER. The message “SAVED OK” displays. The settings are

saved.

3-20 802.1Q VLAN User’s Guide

VLAN Forwarding Configuration Screen

3.7 VLAN FORWARDING CONFIGURATION SCREEN

When to Use

To perform the following functions:

• View the ports included in a VLAN’s Forwarding List.

• Define which ports to include in the VLAN’s Forwarding List.

• Specify the formats of the frames (Tagged or Untagged) that a VLAN

port will forward.

How to Access

Use the arrow keys to highlight the VLAN FORWARDING
CONFIGURATION menu item on the 802.1Q VLAN Configuration

Menu screen and press ENTER. The VLAN Forwarding Configuration
screen displays.

Screen Example

6C105 LOCAL MANAGEMENT
VLAN Forwarding Configuration

Module Type: xxxxx-xx
Slot Number: xx

Current VLAN Ports

Port 15
Port 17
Port 20
Port 23
Port 24
Port 25
Port 35
Port 30

VLAN ID: [4094]

Port: [30]

SAVE PREVIOUS NEXT

VLAN Name: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Port Type
Etherent Frontpanel
Etherent Frontpanel
Etherent Frontpanel
Etherent Frontpanel
Etherent Frontpanel
Etherent Frontpanel
ATM ELAN Finance
ATM PVC VCI-1 VP!-23

ATM PVC VCI-1 VPI-23

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

Frame Format
Untagged
Untagged
Untagged
Untagged
Untagged
Untagged
Tagged
Untagged

[DELETE]

Frame Type: [Untagged]

EXIT

RETURN

25991-08

Figure 3-8 VLAN Forwarding Configuration Screen

802.1Q VLAN User’s Guide 3-21

Chapter 3: VLAN Configuration

Field Definitions

Table 3-5 VLAN Forwarding Configuration Screen Field Definitions
Use this field … To …

Current VLAN
Ports

(Read-Only)

Port Type

(Read-Only)

Frame Format

(Read-Only)

VLAN ID

(Selectable)

VLAN Name

(Read-Only)
ADD/DELETE

(Toggle)

Port (Selectable) Select the port number of the interface being configured.

Frame Type

(Toggle)

See the ports that are currently configured to transmit
frames classified to the selected VLAN.

See the MIB2 interface description for the selected s witch
port.

See the frame format (Tagged or Untagged) for the frames
of the selected VLAN that the port will transmit.

Select the identification of the VLAN under examination.
This screen displays the list of ports currently configured
to transmit frames for the VLAN ID in this field.

See the name associated with the VLAN ID.

Swap the action taken to add or delete a port from the
VLAN Forwarding List.

The MIB2 interface description of the port appears to the
right of the Port field. In Section 3-8, ATM PVC VCI-1
VPI-23 is the Port Type for Port 30.

Select the format of frames (Tagged or Untagged) that will
be transmitted by the selected port for this VLAN. The
default is Untagged.

3.7.1 Viewing Current VLAN Ports

To display the VLAN Forwarding List for a particular VLAN, proceed as
follows:

1. Use the arrow keys to highlight the VLAN ID field. Use the SPACE

bar or BACKSPACE to step to the desired VLAN ID and VLAN
Name.

2. Press ENTER. The screen updates to display the VLAN Forwarding

List for the selected VLAN.

3-22 802.1Q VLAN User’s Guide

VLAN Forwarding Configuration Screen

3.7.2 Paging Through VLAN Forwarding List Entries

To display additional entries in the VLAN Forwarding List that do not
appear on the screen, use the NEXT or PREVIOUS commands located at
the bottom of the screen, as follows:

1. To display the next screen, use the arrow keys to highlight NEXT.

Press ENTER to view the entries on the next screen.

2. To display the previous screen, use the arrow keys to highlight

PREVIOUS. Press ENTER to view the entries on the previous screen.

3.7.3 Adding Forwarding List Entries

To add a port to the VLAN Forwarding List, proceed as follows:

1. Use the arrow keys to highlight the VLAN ID field. Use the SPACE

bar or BACKSPACE to step to the desired VLAN ID and VLAN
Name. Press ENTER.

2. Use the arrow keys to highlight the Port field. Step through the

available ports on the module with the SPACE bar or BACKSPACE.

3. Use the arrow keys to highlight the ADD/DELETE field. Press the

SPACE bar to select ADD or DELETE. Press ENTER.
The Forwarding List entry will be added to the list of current VLANs

once the configuration is saved.

4. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

5. Press ENTER. The message “SAVED OK” displays.

The port is added to the VLAN Forwarding List of the selected VLAN.

3.7.4 Deleting Forwarding List Entries

To remove a port from the currently displayed VLAN Forwarding List,
proceed as follows:

1. Use the arrow keys to highlight the VLAN ID field. Use the SPACE

bar or BACKSPACE to step to the desired VLAN ID and VLAN
Name. Press ENTER.

802.1Q VLAN User’s Guide 3-23

Chapter 3: VLAN Configuration

2. Use the arrow keys to highlight the Port field. Step through the

available ports on the module with the SPACE bar or BACKSPACE.

3. Use the arrow keys to highlight the ADD/DELETE field. Press the

SPACE bar to select DEL. Press ENTER.
The Forwarding List entry will be deleted from the list of current

VLANs once the configuration is saved.

4. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

5. Press ENTER. The message “SAVED OK” displays and the port is

deleted from the VLAN Forwarding List of the selected VLAN.

3.7.5 Changing the Frame Format

To change the frame format for a port, proceed as follows:

1. Use the arrow keys to highlight the Port field. Step through the

available ports by pressing the SPACE bar or BACKSPACE.

2. Using the arrow keys, select the Frame Type field. Use the SPACE

bar or BACKSPACE to toggle between Tagged or Untagged.

3. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

4. Press ENTER. The message “SAVED OK” displays.

3.8 PROTOCOL VLAN CONFIGURATION SCREEN

When to Use

To assign a protocol to a VLAN ID on one or more ports on the switch.
This enables the switch to add a particular VLAN identifier with the
specified protocol to each frame that arrives on a configured port. Other
switches receiving the frame will classify the frame according to the
VLAN identifier within the frame. Entries may also be deleted or
modified.

When the frame is transmitted, it is sent to the ports associated with the
VLAN ID as established using the Protocol Port Configuration screen.

3-24 802.1Q VLAN User’s Guide

Protocol VLAN Configuration Screen

How to Access

Use the arrow keys to highlight the PR O TOCOL VLAN
CONFIGURA TION menu item on the 802.1Q VLAN Configuration

Menu screen and press ENTER. The Protocol VLAN Configuration
screen displays.

Screen Example

2E253-49R LOCAL MANAGEMENT

Protocol VLAN Configuration

Module Type: xxxx-xx
Slot Number: xx

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

VLAN ID Protocol Type

0001 0x0800 (IP)
0002 0x0801 (CUSTOM)

VLAN ID: [ 2 ]

Configure Ports: [ ALL PORTS ]

Protocol Type: [ CUSTOM ] Ether type: 0x0800

SAVE

PREVIOUS NEXT

Feature Status:

Configured Ports

ALL PORTS
USER DEFINED PORT LIST

[ ENABLED ]

[ ADD/MODIFY ]

Action:

EXIT

Figure 3-9 Protocol VLAN Configuration Screen

RETURN

25991_23

802.1Q VLAN User’s Guide 3-25

Chapter 3: VLAN Configuration

Field Definitions

Table 3-6 Protocol VLAN Configuration Screen Field Definitions

Use this field … To …

VLAN ID -

upper

part of screen

(Selectable)
Protocol T ype -

upper part of
screen

(Selectable)
Configured

Ports

(Selectable)

VLAN ID

(Modifiable)

Configure Ports
(Toggle)

Display the VLAN IDs currently configured and may be
selected after the screen is saved to call up the Protocol
Ports Configuration screen using the ENTER key.

Display the protocol type associated with the VLAN ID in
the VLAN ID column. This field may be selected after the
screen is saved to call up the Protocol P orts Configuration
screen.

Indicate if a VLAN ID and Protocol Type applies to all
configurable ports or only those listed in the Protocol
Ports Configuration screen for that Priority and Protocol
Type. Configurable ports are all the physical ports and
existing virtual interfaces (such as for ATM).

Enter the VLAN ID which will be assigned to a protocol.
The VLAN ID ma y be one already created or a ne w one . If
a new VLAN ID is entered, it will be added to the VLAN
Configuration with a FID of the same value as the VLAN
ID and a VLAN name of PROTOCOL VLAN. To enter the
VLAN IDs, refer to Section 3.8.2.

Apply the priority and protocol type to all or none of the
configurable ports. The choices are:

ALL PORTS
NO PORTS
NOTE: If ports are added or removed from the port list in

the Priority Ports Configuration screen described in

Section 3.9, the Configured Ports for the particular VLAN

ID and Protocol Type will change from ALL PORTS or NO
PORTS to USER DEFINED PORT LIST in the Protocol
Priority Configuration screen

3-26 802.1Q VLAN User’s Guide

Protocol VLAN Configuration Screen

Table 3-6 Protocol VLAN Configuration Screen Field Definitions (Cont’d)
Use this field … To …

Protocol Type

(Selectable)

Feature Status
(Toggle)

Select one of the following protocol types:
IP – pertains to all IP associated Ether Types (i.e.,

0x0x0800, 0x0806, and, 0x8035).
IPX – pertains to all IPX associated Ether Types (i.e.,

0x8137, 0x8138, and special cases, 0x0100 [LLC Type 1
Encapsulation] and 0x0101 [LLC Type 2 Encapsulation]).

Appletalk – pertains to all Appletalk associated Ether
Types (i.e., 0x809B and 0x80F3).

Netbios – pertains to all Netbios associated Ether Types
(i.e. 0x0102).

Banyan Vines – pertains to all Banyan Vines associated
Ether Types (i.e., 0x0103 and 0x0BAD).

DECNET – pertains to all DECNET associated Ether
Types.

CUSTOM – when this field is chosen, Ether Type “0x0”
displays so the user can input a particular Ether Type.

NOTE: Any Ether type selected or entered in the Ether
type field and saved will become part of the selection in
the protocol field.

For details, refer to Section 3.8.1.
Enables or disables the entries. The entries can be made

but are not affectiv e until this field is set to ENABLED. The
choices for this field are:

ENABLED
DISABLED

Action

(Toggle)

Used to add or delete an entry (Priority) and its protocol.
This field toggles between [ADD/MODIFY] and [DELETE].

ADD/MODIFY– adds the new Priority and Protocol Type
entries (for example, Priority [0] and Protocol Type
[Banyan Vines]).

DELETE – deletes an existing entry with the associated
priority (for example, Priority [0] and Protocol Type
[Banyan Vines]).

802.1Q VLAN User’s Guide 3-27

Chapter 3: VLAN Configuration

Table 3-6 Protocol VLAN Configuration Screen Field Definitions (Cont’d)
Use this field … To …

Ether type

(Modifiable)

Enter the values of a new Ether type when CUSTOM is
selected in the Protocol Type field.The value 0x0 will
display, which can be modified. A protocol may ha v e more
that one Ether Type. Any Ether Type greater than 05dc
(hex) and less than ffff (hex) may be entered. The
maximum number of Ether Types configured per switch is

32. If an attempt is made to enter more that 32, an error
message, “ETHER TYPE T ABLE FULL” displays.

To enter values of a particular Ether Type, refer to

Section 3.8.2.

3.8.1 Displaying the Current Protocol, VLAN ID, and

Port Assignments

In some instances it may be desirable to see which VLAN IDs and the
associated ports that are currently assigned to a particular protocol. To
display this information, proceed as follows:

1. Use the arrow keys to highlight the Protocol field at the bottom of the

screen.

2. Press the SPACE bar to step to the appropriate protocol.

3. Press ENTER. The screen displays all VLAN IDs and associated ports

currently assigned to the selected protocol.

4. If there is more information than the screen can display, use the NEXT

and PREVIOUS command at the bottom of the screen to display the
information.

3.8.2 Assigning a Protocol Family to a VLAN ID

To assign all Ether Types associated with a Protocol Family to a
VLAN ID, proceed as follows:

NOTE

3-28 802.1Q VLAN User’s Guide

The list of Ether Type configurations is searched prior to the list
of “Protocol F amily” configurations when a frame is received on
a switch. This means that if Ether T ype of 0x0800 is configured
on port 10 with VID of 5 and IP is configured on port 10 with
VID of 6, the incoming frame will receive the VID 5 as Ether
Types have priority over “Protocol Family”.

Protocol VLAN Configuration Screen

1. Use the arrow keys to highlight the VLAN ID field at the bottom of

the screen.

2. Enter the VLAN ID. If a new VLAN ID is entered that has not been

created on the switch, use a unique number between 2 and 4094. The
VLAN IDs of 0, 1, and 4095 may not be used for user-defined VLANs.
A FID will automatically be assigned to the new VLAN ID. The FID
assigned will have the same value.

If an illegal number is entered, the Event Message Line will display:
”PERMISSIBLE RANGE FOR VLAN IDS: 2 to 4094” and the field
will refresh with the previous value.

NOTE

Each VLAN ID must be unique. If a duplicate VLAN ID is
entered, the switch assumes that the Administrator intends to
modify the existing VLAN.

3. Use the arrow keys to highlight the Protocol field at the bottom of the

screen.

4. Use the SPACE bar to step to the appropriate protocol type; IP, IPX,

Appletalk, Netbios, Banyan Vines, DECNET, or CUSTOM. If
CUSTOM is selected, Ether Type 0x0 displays. The user’s own Ether
Type can then be entered if necessary.

NOTE

TIP

Any Ether Type entered in the Ether Type field and saved will
become part of the selection in the Protocol field.

To see if there are VLANs currently assigned to the Protocol
displayed in the Protocol field, press ENTER.

5. Use the arrow keys to highlight the Configure Ports field near the

bottom of the screen.

6. Press the SPACE bar to toggle the field to apply the VLAN ID and

Protocol Type entries to either ALL PORTS or NO PORTS.

802.1Q VLAN User’s Guide 3-29

Chapter 3: VLAN Configuration

7. If CUSTOM was selected in the Protocol Type field, use the arrow

keys to highlight the Ether type field. Otherwise, go to step 9.

8. Enter your particular protocol type in the Ether type field.

9. Use the arrow keys to highlight the Action field.

10. Press the SPACE bar to toggle the field to either ADD/MODIFY or

DELETE the settings selected in the VLAN ID and Protocol Type
fields.

11. Press ENTER and the new settings are displayed under the VLAN ID,

Protocol Type, and Configured Ports values.

12. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

13. Press ENTER. The message “SAVED OK” displays and the settings

are saved. A particular line of data displayed may now be highlighted
to display the Protocol Ports Configuration screen, as described in

Section 3.8.3, to view, add, or delete ports from the priority in the

highlighted line.

3.8.3 Displaying the Protocol Types on Current Ports

To display the current ports and port types associated with a VLAN ID,
the Protocol Ports Configuration screen must be displayed. While in that
screen, ports and their port type may be added to, or current ones deleted
from, the VLAN ID. To access the Protocol Ports Configuration screen,
proceed as follows:

1. Highlight the line of information containing the VLAN ID of interest

to display the current ports and port types associated with that VLAN
ID. The entries in the line of information must have been saved before
you can select it to display the Protocol Ports Configuration screen.

2. Press ENTER. The Protocol Ports Configuration screen displays,

showing all current ports and port types associated with that
VLAN ID. For more information about the Protocol Ports
Configuration screen and how to use it, refer to Section 3.9.

3-30 802.1Q VLAN User’s Guide

Protocol Ports Configuration Screen

3.9 PROTOCOL PORTS CONFIGURATION SCREEN

When to Use

To display the current ports and port types associated with a VLAN and
protocol selected in the Protocol VLAN Configuration screen described in

Section 3.8.

NOTE

can be used to access the Protocol Ports Configuration screen
as described below.

How to Access

Use the arrow keys to highlight a line of information under the VLAN
ID/Protocol Type/Configured Ports BitMap columns in the Protocol
Priority Configuration screen and press ENTER. The Protocol Ports
Configuration screen displays.

Screen Example

6C105 LOCAL MANAGEMENT

Protocol Ports Configuration

The line of information selected must have been sa ved bef ore it

Module Type: xxxxx-xx
Slot Number: xx

Current Protocol Ports
15

30

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

Port Type
Ethernet

ATM PVC VCI-1 VPI-23

VLAN ID :
Port: [ 31]

Protocol: 0X800

1

ATM PVC VCI-1 VPI-23

[ DELETE ALL PORTS ]

EXITSAVE PREVIOUS NEXT

RETURN

2599_24

Figure 3-10 Protocol Ports Configuration Screen

802.1Q VLAN User’s Guide 3-31

Chapter 3: VLAN Configuration

Field Definitions

Table 3-7 Protocol Ports Configuration Screen Field Definitions
Use this field … To …

Current
Protocol Ports

(Read-Only)

Port T ype

(Read-Only)

VLAN ID

(Read-Only)

Protocol

(Read-Only)

Port

(Selectable)

DELETE ALL
PORTS

(Selectable)

Display the current ports associated with the VLAN ID.

Display the Port Type associated with the port in the
Current Ports column.

Display the VLAN ID that is in the line of information
highlighted in the Protocol VLAN Configuration screen.

Display the protocol in the line of information highlighted in
the Protocol VLAN Configuration screen.

Step through the ports to select a port to add of deleted
from the VLAN ID shown in the VLAN ID field. When a port
is displayed the associated port type is displayed to the
right of the port number. In Figure 3-10, the port is 31 and
the associated port type is, ATM PVC VCI-1 VPI-23.

Add or delete a port selected in the Port field of the VLAN
ID displayed, or add all ports to, or deleted all ports that
are configurable on the device. All ports includes, all
physical and virtual ports such as ATM ports if supported.
In Figure 3-10, the priority is “0”. The selections are as
follows:

ADD PORT – adds the port selected in the Port field.
ADD ALL PORTS – adds ALL PORTS that are

configurable to the VLAN ID shown in the VLAN ID field.
DELETE PORT – deletes the port selected in the Port

field.
DELETE ALL PORTS – deletes ALL PORTS that are

configurable from the VLAN ID shown in the VLAN ID
field.

3-32 802.1Q VLAN User’s Guide

Quick VLAN Walkthr ough

3.9.1 Adding/Deleting Ports Associated with a VLAN ID

To add or delete ports from a VLAN, proceed as follows:

1. Use the arrow keys to highlight the Port field.

2. Press the SPACE bar to step to the appropriate port number. The

associated protocol is displayed for that port.

3. Use the arrow keys to highlight the DELETE ALL PORTS field.

4. Press the SPACE bar to step to the appropriate selection to ADD

PORT , ADD ALL POR TS, DELETE PORT , or DELETE ALL PORTS
from the VLAN ID shown in the VLAN ID field.

5. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

6. Press ENTER. The message “SAVED OK” displays and the settings

are saved.

3.10 QUIC K VLAN WALKTHROUGH

The procedures below provide a short tutorial walkthrough that presents
each of the steps necessary to configure a new VLAN, assign a port to it,
and check the Port VLAN List of the port. You may wish to follow this
walkthrough from start to finish before attempting to configure your own
VLANs.

This walkthrough begins at the 802.1Q VLAN Configuration Menu
screen for a 6C105 chassis. Follow the instructions in your device user’s
guide to navigate to this Local Management screen.

NOTE

The screens displayed by your devices may be marginally
different from those shown in the illustrations for this
walkthrough.

1. On the 802.1Q VLAN Configuration Menu screen, use the arrow keys

to highlight the DEVICE VLAN CONFIGURATION menu item.
Press ENTER. The Device VLAN Configuration screen displays.

2. In this walkthrough, we will not change the setting of the Forward

Default VLAN Out All Ports fields from their default setting of NO.

802.1Q VLAN User’s Guide 3-33

Chapter 3: VLAN Configuration

3. Use the arrow keys to highlight the VLAN ID field. Assign a number

to a new VLAN by typing the number “2” in the VLAN ID field.

4. Use the arrow keys to highlight the FID field. In this example we will

assign the new VLAN to FID 2 by typing the number “2” in the FID
field.

5. Use the arrow keys to highlight the VLAN Name field. Type “TEST

VLAN” in the VLAN Name field. Press ENTER.

6. Use the arrow keys to highlight the ADD/DEL field.

7. Press the SPACE bar to toggle the field to ADD. Press ENTER. The

VLAN is added to the list.

8. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The message “SAVED OK” displays. The
screen refreshes and VLAN 2, the TEST VLAN has been added to the
Device VLAN Configuration screen and all learning of MAC
addresses will be updated in FID 2. The screen should now look like

Figure 3-11.

NOTE

3-34 802.1Q VLAN User’s Guide

This new VLAN is currently disabled, as the DISABLED field to
the far right shows. When all the rules and settings for the
VLAN are in place, it will be necessary to return to this screen
and enable the VLAN.

Module Type: xxxxx-xx
Slot Number: xx

Quick VLAN Walkthr ough

6C105 LOCAL MANAGEMENT

Device/VLAN Configuration

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

Forward Default VLAN Out All Ports: [NO]

EXIT

Admin Status

[Enabled]
[Disabled]

RETURN

25993-09

VLAN ID
1
2

VLAN ID: 1 FID: 2 VLAN Name: TEST VLAN [ADD]

SAVE

FID
1
2

VLAN Name
DEFAULT VLAN
TEST VLAN

Figure 3-11 Walkthrough Stage One

It is now time to assign a port to this new VLAN.

9. Use the arrow keys to highlight the RETURN command at the bottom

of the screen. Press ENTER. The 802.1Q VLAN Configuration Menu
screen displays. Use the arrow keys to select the PORT
ASSIGNMENT CONFIGURATION menu item and press ENTER.
The Port Assignment Configuration screen displays.

NOTE

For the purposes of this walkthrough, port 3 will be configured.

10. Use the arrow keys to highlight the VLAN ID field for the module and

port combination you wish to change.

NOTE

802.1Q VLAN User’s Guide 3-35

As this port will connect to a single workstation, and is not to be
used for switch-to-switch communications, it is not necessary
to change the PORT MODE from the default setting of
HYBRID.

Chapter 3: VLAN Configuration

11. Use the SPACE bar to step sequentially through the previously

configured VLAN ID numbers. When the number 0002 (the new
VLAN ID) is displayed, the FID field updates to 0002, and the VLAN

Name field updates showing the name assigned to this VLAN, TEST
VLAN.

12. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. The PVID for Port 3 is now configured to
the TEST VLAN. The TEST VLAN is also added to the Port VLAN
List for Port 3 with a frame format of Untagged. The screen should
now look like Figure 3-12.

6C105 LOCAL MANAGEMENT

Port Assignment Configuration

Module Type: xxxxx-xx
Slot Number: xx

Port

1
2
3
4
5
6
7
8
9
10
11
12

Port Mode

[1D TRUNK]
[1Q TRUNK]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]

VLAN ID

[0001]

[0001]
[0002]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]

FID

0001
0001
0002
0001
0001
0001
0001
0001
0001
0001
0001
0001

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

VLAN Name

Default VLAN
Default VLAN
TEST VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN
Default VLAN

SAVE PREVIOUS NEXT

EXIT

RETURN

25992-10

Figure 3-12 Walkthrough Stage Two

Now that port 3 belongs to the TEST VLAN, we will designate one port
as a 1Q Trunk port for a connection to another VLAN aware switch. This
1Q Trunk port will carry traffic from all VLANs, allowing VLAN frames
to maintain their VLAN ID across multiple switches.

NOTE

3-36 802.1Q VLAN User’s Guide

For the purposes of this walkthrough, port 10 will be configured
as the trunk port.

Quick VLAN Walkthr ough

13. Use the arrow keys to highlight the Port Mode field for port 10. Use

the SPACE bar or BACKSPACE key to step sequentially through the
possible settings of the port until 1Q TRUNK is displayed.

14. Use the arrow keys to highlight the SAVE command at the bottom of

the screen. Press ENTER. Port 10 is now acting as a 1Q Trunk port and
every VLAN is in its Port VLAN List. The frame format for every
VLAN is also set to tagged. The screen should now look like

Figure 3-13.

6C105 LOCAL MANAGEMENT
Port Assignment Configuration

Module Type: xxxxx-xx
Slot Number: xx

Port

1
2
3
4
5
6
7
8
9
10
11
12

Port Mode

[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[HYBRID]
[1Q TRUNK]
[HYBRID]
[HYBRID]

VLAN ID

[0001]

[0001]
[0002]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]
[0001]

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

VLAN Name

DEFAULT VLAN
DEFAULT VLAN
TEST VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN
DEFAULT VLAN

SAVE PREVIOUS NEXT

EXIT

RETURN

25991-11

Figure 3-13 Walkthrough Stage Three

Now that the TEST VLAN and the 1Q Trunk connection are set up, we
can proceed to activate the TEST VLAN.

802.1Q VLAN User’s Guide 3-37

Chapter 3: VLAN Configuration

15. On the 802.1Q VLAN Main Menu screen, use the arrow keys to

highlight the DEVICE VLAN CONFIGURATION menu item.
Press ENTER. The Device VLAN Configuration screen, Figure 3-14,
displays.

6C105 LOCAL MANAGEMENT

Device/VLAN Configuration

Module Type: xxxxx-xx
Slot Number: xx

Forward Default VLAN Out All Ports: [NO]

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

EXIT

Admin Status

[Enabled]
[Enabled]

RETURN

25993-12

VLAN ID
1
2

VLAN ID: 1 FID: 2 VLAN Name: DEFAULT VLAN [ADD]

SAVE

FID
1
2

VLAN Name
DEFAULT VLAN
TEST VLAN

Figure 3-14 Walkthrough Stage Four

16. Use the arrow keys to highlight the Admin Status field of

VLAN ID 2, the TEST VLAN.

17. Press the SPACE bar to toggle the field to display Enabled.

18. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

19. Press ENTER. The message “SAVED OK” displays. The switch

activates the new VLAN.

This effectiv ely completes the configuration of a single VLAN, assigning
it to a port, and configuring the switch to forward the frames received on
that port to be forwarded with the VLAN information included in the
frame.

3-38 802.1Q VLAN User’s Guide

Quick VLAN Walkthr ough

The Port VLAN List of any port on the device can also be checked at any
time using the Port Filtering Configuration screen. A list of all ports
eligible to transmit frames for a given VLAN will also be listed on the
VLAN Forwarding Configuration screen. Each port can also be set to
filter out (drop) incoming frames that have VLAN tags that do not match
with any of those in its Port VLAN List, and also filter out all untagged
frames received by the port. As a default neither function is activated.

In this walkthrough, we will show how to display the Port VLAN List of
port 10 and set the port to filter out all untagged frames that it receives.

20. On the 802.1Q VLAN Main Menu screen, use the arrow keys to

highlight the PORT FILTERING CONFIGURATION menu item.
Press ENTER. The Port Filtering Configuration screen displays.

21. Use the arrow keys to highlight the Port field.

22. Press the SPACE bar to step the field to display 2.

23. Use the arrow keys to highlight the Filter All Untagged Frames field.

24. Press the SPACE bar to toggle the field to display YES.

25. Use the arrow keys to highlight the SAVE command at the bottom of

the screen.

26. Press ENTER. The message “SAVED OK” displays. The Port

Filtering Configuration screen displays the Port VLAN List for port 2
and the Filtering All Untagged Names field is set to YES as shown in

Figure 3-15.

802.1Q VLAN User’s Guide 3-39

Chapter 3: VLAN Configuration

6C105 LOCAL MANAGEMENT

Port Filtering Configuration

Module Type: xxxxx-xx
Slot Number: xx

Port VLAN List

VLAN ID
0001
0001

VLAN Name
DEFAULT VLAN
1Q TRUNK

Firmware Revision: XX.XX.XX
BOOTPROM Revision: XX.XX.XX

Port : [10]

SAVE PREVIOUS NEXT

Filter Using VLAN Lists: [NO]

Filter All Untagged Frames: [YES]

EXIT

RETURN

25992-20

Figure 3-15 Final Walkthrough Stage

This effectively completes the displaying of the Port VLAN List and the
setting of the port filtering of all untagged frames.

3-40 802.1Q VLAN User’s Guide

CHAPTER 4

EXAMPLES

This chapter provides examples of how VLAN aware SmartSwitches can
be configured to group users at the port level to create VLANs in existing
networks. Each example presents a problem and shows how it is solved
by configuring the switches using the VLAN Local Management screens.
The actual procedures and screens used to configure a VLAN aware
switch are covered in Chapter 3, VLAN Configuration. Also provided in
the discussion of each example is a description of how the frames
transmitted from one user would traverse the network to its target device.

4.1 EXAMPLE 1, SINGLE SWITCH OPERATION

This first example looks at the configuration of a single Ethernet switch
for VLAN operation. In this example, two groups of three users are to be
assigned to two VLANs to isolate them from one another. The blue users
(B1, B2, B3) are to be kept completely separate from the red users (R1,
R2, R3). Figure 4-1 shows the initial state of the switch.

802.1Q Switch

1

4

R2

2

R3

Figure 4-1 Example 1, Single Switch Operation

802.1Q VLAN User’s Guide 4-1

3 6

5

B3R1

B2

B1

2263_11

Chapter 4: Examples

4.1.1 Solving the Problem

To set up this switch, users will be assigned to two new VLANs, red
stations to the Red VLAN, and blue stations to the Blue VLAN. The
information below describes how the switch is configured to create these
two VLANs and how users are assigned to them.

1. First, the switch is set for 802.1Q operation. Since traffic isolation is

to be based on VLAN membership alone, the switch is set so the Red
VLAN is a member of FID 2 and the Blue VLAN is a member of FID
3 from the Device/VLAN Configuration screen.

2. The Administrator uses the Device/VLAN Configuration screen to

define the two VLANs for this switch; the Red VLAN, with a VLAN
ID of 002, and the Blue VLAN, with a VLAN ID of 003.

3. The Administrator brings up the Port Assignment Configuration

screen and assigns the ports to the VLANs.

• Ports 1, 2, and 3: VLAN ID 002 (Red VLAN)

• Ports 4, 5, and 6: VLAN ID 003 (Blue VLAN)

4. Now that the ports have been assigned, the VLANs are enabled from

the Device/VLAN Configuration screen.

802.1Q Switch

1

VLAN ID 002

4

VLAN ID 003

R2

2

R2

Figure 4-2 Switch Configured for VLANs

4-2 802.1Q VLAN User’s Guide

3 6

5

VLAN ID 003VLAN ID 002

VLAN ID 003VLAN ID 002

B3R1

B2

B1

2263_12

Example 1, Single Switch Operation

The switch will now classify each frame received as belonging to either
the Red or Blue VLANs. T raf fic from one VLAN will not be forwarded to
the members of the other VLAN, and all frames transmitted by the switch
will be normal, untagged Ethernet frames.

4.1.2 Frame Handling

This section describes the operations of the switch when two frames are
received. The first frame is a broadcast sent by station R1.

1. Station R1 transmits the broadcast frame. The switch receives this

frame on Port 1. As the frame is received, the switch classifies it. The
frame is untagged, so the switch classifies it as belonging to the VLAN
that Port 1 is assigned to, the Red VLAN.

2. At the same time, the switch adds the source MAC address of the

frame and the VLAN associated with port 1 to its Source Address
Table in FID 2. In this fashion it learns that station R1 is located out
Port 1.

3. Once the frame is classified, its destination MAC address is examined.

The switch discovers that the frame is a broadcast, and treats it as it
would any other unknown destination MAC address. The switch
forwards the frame out all ports in the Red VLAN’s Forwarding List
except for the one that received the frame. In this case, the frame is
sent to Ports 2 and 3.

The second frame is a unicast, where station R2 responds to station R1’s
broadcast.

4. Station R2, having received and recognized the broadcast from R1,

transmits a unicast frame as a response. The switch receives this frame
on Port 2. The switch classifies this new untagged frame as belonging
to the Red VLAN.

5. The switch adds the source MAC address and VLAN for station R2 to

its Source Address Table in FID 2, and checks the Source Address
Table for the destination MAC address given in the frame. The switch
finds the MAC address and VLAN in this table, and recognizes that
the MAC address and VLAN match for R1 is located out Port 1.

802.1Q VLAN User’s Guide 4-3

Chapter 4: Examples

6. The switch examines its VLAN configuration information and

determines that the frame for Red VLAN is allowed to be forwarded
out Port 1 and that it must be sent in an untagged format.

7. The switch forwards the frame out Port 1. Any other unicast

transmissions between stations R1 and R2 will be handled identically.

4.2 EXAMPLE 2, VLANS ACROSS MULTIPLE

SWITCHES

This second example investigates the steps that must be taken to set up
VLANs across multiple 802.1Q VLAN switches. This includes the
configuration and operation of 1Q Trunks between 802.1Q VLAN
switches.

As shown in Figure 4-3, two companies, “Redco” and “Blue Industries”,
share floors 2 and 4 in a building where the network infrastructure is
supplied by the building owner. The objective is to completely isolate the
network traffic of the two companies by limiting the user’s traffic through
the ports of two switches, thus maintaining security and shielding the
network traffic from each company. This example will show the use and
configuration of a 1Q Trunk connection and the creation of VLANs across
multiple switches.

4-4 802.1Q VLAN User’s Guide

Example 2, VLANs Across Multiple Switches

Redco

User A

Floor 4

Floor 3

Blue Industries

File Server

Floor 2

Blue Industries

Bridge 1 Bridge 2

Red VLAN

Red VLAN

Bridge 3

Blue VLAN

Blue VLAN

2

1

3

4

4

2

1

3

2

Redco

Blue VLAN

Blue VLAN

Bridge 4

Red VLAN

Red VLAN

File Server

Floor 1

User 802.1D Legacy Bridge 802.1Q VLAN Aware Switch

File Server

22632_13

Figure 4-3 Example 2, VLANs Across Multiple Switches

4.2.1 Solving the Problem

To solve the problem in this example, the users are assigned to VLANs
using Switch 4 and Switch 2 as shown in Figure 4-3. Redco users are
assigned to the Red VLAN and Blue Industries users to the Blue VLAN.
The following information shows how Switch 4 and Switch 2 are
configured to create the two VLANs to isolate the users of the two
companies from one another on the network using the existing
infrastructure.

802.1Q VLAN User’s Guide 4-5

Chapter 4: Examples

Switch 4

Switch 4 is set as follows:

1. Two VLANs are added to the list of VLANs in the Device/VLAN

Configuration screen and assigned to a FID. In this example they are
as follows:

• VLAN ID 2, FID 2, with a VLAN Name of Red

• VLAN ID 3, FID 3, with a VLAN Name of Blue

Because the VLANs are assigned to two separate FIDs, the users on
VLAN ID 2 and VLAN ID 3 cannot communicate with each other.

2. Ports 1 and 3 are assigned to the Port VLAN ID (PVID) as follows

using the Port Assignment Configuration screen:

• Port 1, VLAN ID: 2 for the Red VLAN

• Port 3, VLAN ID: 3 for the Blue VLAN

This causes the switch to classify all untagged frames received as
belonging to the VLAN specified by each port PVID and to replace the
previous PVID information in the port VLAN List with the new PVID
information. This makes Port 1 part of the Red VLAN, Port 3 part of
the Blue VLAN, and both are set as VLAN frame format of untagged.

3. Port 4 is configured as a 1Q Trunk port as follows using the Port

Assignment Configuration screen:

• Port Mode: 1Q Trunk

Port 4 is set as an 802.1Q Trunk port, which makes the port eligible to
transmit to all VLANs, and all frames forwarded out this port are
forwarded as tagged frames. By default there is no PVID associated
with the trunk port and the port remains as a member of the Default
VLAN. With the original classification information inserted in the
frame Tag Header, the receiving switch will maintain the original
frame classification.

4-6 802.1Q VLAN User’s Guide

Example 2, VLANs Across Multiple Switches

Switch 2

Switch 2 is set as follows:

1. Two VLANs are added to the list of VLANs using the Device/VLAN

Configuration screen and assigned to a FID. In this example they are
as follows:

• VLAN ID 2, FID 2, with a VLAN Name of Red

• VLAN ID 3, FID 3, with a VLAN Name of Blue

2. A Port VLAN ID is assigned to each port (1 and 3) as follows using

the Port Assignment screen:

• Port 1, VLAN ID: 223 for the Blue VLAN

• Port 3, VLAN ID: 222 for the Red VLAN

These settings change the configuration of the switch, so that Port 1 is
part of Blue VLAN, Port 3 is part of Red VLAN, and both are set as
frame type of untagged.

3. Port 2 is configured as a 1Q Trunk port as follows using the Port

Assignment Configuration screen:

• Port 2, Port Mode: 1Q Trunk

Port 2 is set as an 802.1Q Trunk port, which makes its Port VLAN List
contain all VLANs and sets all frames forwarded out this port as
tagged frames. This completes the transmission path between
Switch 4 and Switch 2.

802.1Q VLAN User’s Guide 4-7

Chapter 4: Examples

4.2.2 Frame Handling

The following describes how, when User A attempts to log on to the File
Server on Bridge 4, the frames from User A are classified on Switch 4 and
traverse the network. In this example, the MAC address of User A is “Y”
and the MAC address for the File Server is “Z”. The following description
includes illustrations to help understand how the frames flow through the
network.

1. User A sends a frame with a Broadcast Destination Address in an

attempt to locate the File Server. The frame is received on User A’s
port of Bridge 1 and, because the frame is a broadcast frame, it is
transmitted out all ports of Bridge 1 as shown in Figure 4-4.

Redco Blue Industries

2

1

3

4

4

Bridge 2

Blue VLAN

Blue VLAN

Floor 4

User A

Bridge 1

Red VLAN

Red VLAN

2263_14

Figure 4-4 Bridge 1 Broadcasts Frames

2. Switch 4 receives the frame from Bridge 1 and immediately classifies

it as belonging to the Red VLAN. After the frame is classified,
Switch 4 checks the Destination Address and, upon discovering that it
is a Broadcast Destination Address, forwards the frame out all ports in
the Red VLAN Forwarding List excluding Port 1, which received the
frame. In this example, it is only Port 4.

Switch 4 updates its Source Address Table in FID 2 if it didn’t already
have a dynamic entry for MAC address “Y” in FID 2. Because
Switch 4 received the frame on Port 1, it does not forward the frame
out that port, but does forward the frame to Port 4.

The frame is transmitted to Switch 2 with a VLAN Tag Header
inserted in the frame. The VLAN Tag Header indicates that the frame
is classified as belonging to the Red VLAN. Figure 4-5 shows the path
taken to this point to reach Switch 2.

4-8 802.1Q VLAN User’s Guide

Example 2, VLANs Across Multiple Switches

The VLAN Tag Header is inserted because Switch 4, Port 4 is
designated as an 802.1Q Trunk port. In this case, the Port Mode setting
for Port 4 is 802.1Q Trunk and the VLAN Frame format for that
VLAN is tagged.

Redco

User A

Floor 4

Floor 3

Blue Industries

Floor 2

Blue Industries

Bridge 1 Bridge 2

Red VLAN

Red VLAN

Bridge 3

Blue VLAN

Blue VLAN

2

1

3

4

4

2

1

3

2

Redco

Blue VLAN

Blue VLAN

Bridge 4

Red VLAN

Red VLAN

Figure 4-5 Transmitting to Switch 4

File Server

22631_15

3. When Switch 2 receives the tagged frame on its Port 2, it checks the

frame’s VLAN Tag Header and determines that the frame is classified
as belonging to the Red VLAN, and that the frame is a broadcast
frame. Switch 2 forwards the frame to all ports in the Red VLAN
Forwarding List excluding Port 2, which received the frame. In this
example, the only eligible port is Port 3, which connects to Bridge 4.
Switch 2 checks its Forwarding List, which specifies that the VLAN
frame type for that port is untagged. Switch 2 then updates its Source
Address Table in FID 3 for MAC address “Y” if necessary. The
untagged frame is then transmitted out Port 3 to Bridge 4. Bridge 4
forwards the frame out all its ports because it is a broadcast frame, and
the server receives it as shown in Figure 4-6.

802.1Q VLAN User’s Guide 4-9

Chapter 4: Examples

Floor 3

Blue Industries

Bridge 3

Blue VLAN

Blue VLAN

Redco

2

3

1

2

Bridge 4

Red VLAN

Red VLAN

File Server

Floor 2

Figure 4-6 Transmitting to Bridge 4

2263_16

4. The File Server responds with a unicast frame to User A. All switches

between the File Server and User A have an entry in their respective
Source Address Tables identifying which port to use for forwarding
the frame to User A, MAC address “Y” in FID 3. All switches update
their Source Address Tables for the File Server’s MAC address “Z” as
the frame is forwarded through the switch fabric to User A. The

802.1D switches update their Source Address Tables based on the
source MAC address and receive port and the 802.1Q switches update
their databases based on the source MAC address, VLAN, and receive
port.

5. The frame from the File Server is received on Switch 2, and forwarded

to Switch 1 as a tagged frame classified as belonging to the Red
VLAN. Switch 1 removes the tag and forwards the frame to Bridge 1,
which in turn forwards the frame out of the port attached to User A.
All subsequent frames between User A and the File Server are
forwarded through the switch fabric in the same manner.

4.3 EXAMPLE 3, 1D TRUNK CONNECTION TO 802.1Q

VLAN NETWORK

This example illustrates the use of a 1D Trunk to connect a device to a
network of 802.1Q VLAN switches.

In this example, a merger has taken place between the companies in the
previous example, Redco and Blue Industries. The two companies have
become divisions within a single corporation, Green Incorporated.

4-10 802.1Q VLAN User’s Guide

Example 3, 1D Trunk Connection to 802.1Q VLAN Network

As illustrated in Figure 4-7, a third group of stations, the Green
Incorporated staff, is added to the facility. Also, the Green Incorporated
Network Administrators want to add a Mail Server to the network on the
first floor.

User B

Floor 4

Floor 3

Floor 2

Green Incorporated.

Bridge 1 Bridge 2

Red VLAN

Red VLAN

Bridge 3

Blue VLAN

Blue VLAN

Green VLAN

Green VLAN

2

1

3

4

4

2

1

3

2

4

2

1

3

1

Blue VLAN

Blue VLAN

Bridge 4

Red VLAN

Red VLAN

Mail Server

File Server

Floor 1

User 802.1D Legacy Bridge 802.1Q VLAN-Aware Switch

Server

22631_17

Figure 4-7 Example 3, 1D Trunk Connection to 802.1Q VLAN Network

The Green Incorporated Network Administrators want to continue to
separate normal network traffic between the Blue and Red VLANs, and
create a new isolated VLAN for Green, Incorporated users. All divisions
in the facility are to have equal access to the Mail Server on the first floor.

802.1Q VLAN User’s Guide 4-11

Chapter 4: Examples

4.3.1 Solving the Problem

Much of the existing network configuration can remain as it was for

Example 2, VLANs Across Multiple Switches. However, the Forward

Default VLAN Out All Ports must be set to YES on Switch 4 and 2, and a
new 1Q Trunk port must be activated and configured on Switch 2. There
are no other real changes to the network above the first floor.

Switch 4

Switch 4 is set as follows:

1. The Forward Default VLAN Out All Ports is set to YES using the

Device/VLAN Configuration screen. This adds the Default VLAN to
the Port VLAN List of every switch port and all VLANs become
members of FID 1. This allows all traffic received from the mail server
via Switch 2 and Switch 1 to be received and classified to the Default
VLAN of Switch 4.

Switch 2

Switch 2 is set as follows:

1. The Forward Default VLAN Out All Ports is set to YES using the

Device/VLAN Configuration screen. This adds the Default VLAN to
the Port VLAN List of every switch port and all VLANs become
members of FID 1.

2. The port mode of Port 4 is set using the Port Assignment screen:

• Port 4, Port Mode: 1Q Trunk

This causes Port 4 to be set as an additional 802.1Q Trunk port, which
makes its Port VLAN List contain all VLANs, and all frames
forwarded out this port are forwarded as tagged frames.

Switch 1

Switch 1 needs to be added to the network backbone to handle traffic from
the Green Incorporated network and the mail server. To accomplish this
Switch 1 is configured as follows:

1. One VLAN is added to the list of VLANs in the Device/VLAN

Configuration screen. In this example, Switch 1 is set as follows:

• VLAN ID 4, FID 4, with a VLAN Name of Green

4-12 802.1Q VLAN User’s Guide

Example 3, 1D Trunk Connection to 802.1Q VLAN Network

2. The Forward Default VLAN Out All Ports is set to YES using the

Device/VLAN Configuration screen. This adds the Default VLAN to
the Port VLAN List of every switch port and all VLANs become
members of FID 1.

3. A Port VLAN ID is assigned to Port 1 using the Port Assignment

screen, as follows:

• Port 1, VLAN ID: 224 for the Green VLAN

This setting changes the configuration of the switch, so that Port 1 is
part of the Green VLAN and is set to transmit a frame type of
untagged.

4. The port mode of Ports 2 and 3 are set using the Port Assignment

screen:

• Port 2, Port Mode: 1Q Trunk

• Port 3, Port Mode: 1D Trunk

Port 2 is set as an 802.1Q Trunk port, which makes the port eligible to
transmit frames of all VLANs, and sets all frames forwarded out this
port as tagged frames.

Port 3 is set as a 1D Trunk port, where frames classified as belonging
to any VLAN are forwarded untagged, and received frames are
classified as belonging to the Default VLAN. This allows the Mail
Server to send/receive mail traffic to/from all VLAN users on the
network backbone,

4.3.2 Frame Handling

The following describes how, when User B attempts to contact the Mail
Server on Switch 1, the frames are classified on Switch 4 and traverse the
network.

1. User B sends a broadcast frame in an attempt to contact the Mail

Server. The frame enters Bridge 1 and, being a broadcast, is forwarded
to all ports. Bridge 1 learns User B’s MAC address from the Source
Address field of the frame and adds it to its Source Address Table in
FID 1.

802.1Q VLAN User’s Guide 4-13

Chapter 4: Examples

2. Switch 4 receives the frame and classifies this new untagged frame as

belonging to the Red VLAN. Since the frame is a broadcast, it is
forwarded to any ports that are classified as eligible to receive Red
VLAN frames. Switch 4 also updates its Source Address Table for
FID 1, identifying User B as being located out Port 1.

On Switch 4, the only port eligible to receive Red VLAN frames is
Port 4, the 1Q Trunk. The frame is forwarded out Port 4 with the Red
VLAN Tag header being added, as shown in Figure 4-8.

User B

2

1

3

4

4

Blue VLAN

Blue VLAN

2263_18

Floor 4

Bridge 1 Bridge 2

Red VLAN

Red VLAN

Figure 4-8 Bridge 1 Broadcasts Frames

3. Switch 2 receives the tagged Red VLAN frame on Port 2, as shown in

Figure 4-9. The VLAN Tag in the frame is maintained, classifying the

frame as belonging to the Red VLAN. The switch forwards the
broadcast frame out all the eligible ports, Ports 3 and 4. Switch 2
simultaneously updates its Source Address Table for FID 1 to reflect
the location of User B (Port 2).

The frame forwarded out Port 3 has its VLAN Tag stripped before
transmission, and it is passed to Bridge 4 as a normal broadcast frame.
The frame that is transmitted out Port 4, the 1Q Trunk, retains its
VLAN tag.

4-14 802.1Q VLAN User’s Guide

Floor 3

Example 3, 1D Trunk Connection to 802.1Q VLAN Network

Floor 2

Bridge 3

Blue VLAN

Blue VLAN

2

1

3

2

4

Bridge 4

Red VLAN

Red VLAN

File Server

2263_19

Figure 4-9 Switch 2 Forwards to 1Q Trunk

4. When Switch 1 receives the tagged broadcast frame, it also examines

the tag and classifies the frame as belonging to the Red VLAN. This
broadcast frame is then sent to all ports eligible to receive Red VLAN
frames. In this case only the 1D trunk, Port 3, is eligible, as it is
considered a member of all VLANs for forwarding purposes. The
VLAN Tag is stripped from the frame and the frame is transmitted out
Port 3 as shown in Figure 4-10. The Source Address Table, FID 1 for
Switch 1 is updated to contain User B.

Floor 2

Green, Inc.

Green VLAN

Green VLAN

2

3

1

1

4

Mail Server

Floor 1

2263_20

Figure 4-10 Switch 1 Forwards to 1D Trunk

5. The Mail Server receives the broadcast frame and recognizes it. The

Mail Server responds with a unicast frame to User B. This frame
crosses the 1D Trunk and is received by Switch 1. Switch 1 classifies
the unicast frame as belonging to the Default VLAN (the only
membership for the 1D Trunk port).

802.1Q VLAN User’s Guide 4-15

Chapter 4: Examples

Switch 1 checks the Filtering Database for the MAC address of
User B. User B’s MAC address is located, and Port 2 is identified as
User B’s location. The frame is then checked for eligibility and frame
format for Port 2. Since Port 2 is a 1Q Trunk port, it is eligible to
transmit frames for all VLANs. The frame is tagged and transmitted
out Port 2.

The switch also recognizes the MAC address of User B in its Source
Address Table, FID 1, and updates that table to contain the MAC
address and port combination of the Mail Server.

6. This tagged unicast frame is received by Switch 2. The frame is

already tagged as belonging to the Default VLAN, so no classification
needs to be done. The switch recognizes User B’s MAC address in its
Source Address Table, FID 1, and updates that table to contain the
Mail Server’s MAC address and port combination.

The switch checks the Filtering Database for the MAC address of
User B. User B’s MAC address is located, and Port 2 is identified as
the location of User B. The frame is checked for eligibility and frame
format for Port 2. Since Port 2 is a 1Q Trunk port, it is eligible to
transmit frames for all VLANs. The frame is tagged and transmitted
out port 2.

7. Switch 4 receives the frame on its 1Q Trunk port, Port 4, and examines

the frame’s Tag. The frame maintains its Default VLAN classification.
The switch also refers to its Source Address Table, FID 1, to see if it
can locate an entry for User B. User B is found to be located on Port 1.
The switch also updates its Source Address Table, FID 1, with the port
and MAC address combination for the Mail Server.

The switch examines the Filtering Database and locates the MAC
address entry for User B and Port 1. The frame is then checked for
eligibility and frame format for Port 1. As Port 1 is considered eligible
to transmit to the Default VLAN, the frame is transmitted out Port 1
without a VLAN Tag.

8. Bridge 1 receives the frame and recognizes User B’s MAC address.

The frame is forwarded to the correct port and the bridge’s Source
Address Table is updated with an entry for the Mail Server’s MAC
address. User B receives the Mail Server’s response. Any further
unicast traffic between the Mail Server and User B will be handled in
the same fashion by the switches in the network.

4-16 802.1Q VLAN User’s Guide

Example 4, Isolating Network Traffic According to Protocol

4.4 EXAMPLE 4, ISOLATING NETWORK TRAFFIC

ACCORDING TO PROTOCOL

This final example illustrates how to restrict AppleTalk protocol traffic of
a network to prevent unwanted multicast frames from slowing down the
whole network and yet be able to send and receive frames associated with
other protocols.

In this example, illustrated in Figure 4-7, the Publications Department is
relocating from another site to the third floor. This netw ork will consist of
six computers and a printer using several protocols including the
AppleTalk protocol. A characteristic of the AppleTalk protocol is to send
all frames as multicast frames. These multicast frames will be isolated to
a VLAN (Grey VLAN) to prevent them from slowing down the other
networks.

A second VLAN (Yellow VLAN) will be established to handle traffic of
other protocols. The Publications Department users will have access to
the mail server on the first floor along with the Red, Blue, and Green
VLANs.

802.1Q VLAN User’s Guide 4-17

Chapter 4: Examples

User B

Floor 4

Floor 3

Floor 2

Green, Inc.

Bridge 1 Bridge 2

Red VLAN

Red VLAN

Bridge 3

Blue VLAN

Blue VLAN

Green VLAN

Green VLAN

2

1

3

4

4

2

1

3

3

4

2

1

3

2

4

2

1

3

1

Blue VLAN

Blue VLAN

Publications

ellow VLAN

YYellow VLAN

Red VLAN

Red VLAN

Mail Server

Bridge 4

1

2

3

4
5

5

6

78

Grey VLAN

Grey VLAN

Printer

File Server

Floor 1

User 802.1D Legacy Bridge 802.1Q VLAN-Aware Switch

Server

2599_18

Figure 4-11 Example 4, Isolating Traffic According to Protocol

4.4.1 Solving the Problem

Much of the existing network configuration can remain as it was for

Example 3, 1D Trunk Connection to 802.1Q VLAN Network. However,

Switch 3, Switch 5, and the devices that will make up Publication’s Grey
VLAN have been added.

4-18 802.1Q VLAN User’s Guide

Example 4, Isolating Network Traffic According to Protocol

Switch 5 will be configured to isolate all AppleTalk protocol frame traffic
to the devices in the Grey VLAN and all other protocol traffic to the
Yellow VLAN. Switch 3 will link the traffic from Switch 5 to the
buildings network backbone.

Two 1Q Trunk ports must be activated and configured on Switch 3, and
one 1Q Trunk port must be activated and configured on Switch 4.

Ports 2, 3, 4, 5, 6, 7, and 8 of Switch 5 are connected to the Publication
Department devices. These ports will be configured to classify all
AppleTalk frames into the AppleTalk VLAN (Grey). The same ports will
also be configured to classify all other protocol frames into a second
VLAN (Yellow). Port 1 will be assigned to the Yellow VLAN to handle
the traffic between Switch 3 and 5.

Switch 3

Switch 3 is set as follows:

1. One VLAN is added to the list of VLANs in the Device/VLAN

Configuration screen. In this example, Switch 3 is set as follows:

• VLAN ID 5, FID 5, with a VLAN Name of Yellow

2. The Forward Default VLAN Out All Ports is set to YES using the

Device/VLAN Configuration screen. This adds the Default VLAN to
the Port VLAN List of every switch port and all VLANs become
members of FID 1.

3. A Port VLAN ID is assigned to Port 3 using the Port Assignment

screen, as follows:

• Port 3, VLAN ID: 5, FID 5

4. The port mode of Ports 2 and 4 are set using the Port Assignment

screen:

• Port 2, Port Mode: 1Q Trunk

• Port 4, Port Mode: 1Q Trunk

Ports 2, and 4 are set as 802.1Q Trunk ports, which makes these ports
eligible to transmit frames of all VLANs, and sets all frames
forwarded out these ports as tagged frames. This allows traffic from
Switch 4 to reach Switch 2 on the network backbone.

802.1Q VLAN User’s Guide 4-19

Chapter 4: Examples

Switch 5

Switch 5 is set as follows:

1. Two VLANs are added to the list of VLANs in the Device/VLAN

Configuration screen. In this example, it is set as follows:

• VLAN ID 5, FID 5, with a VLAN Name of Yellow

• VLAN ID 6, FID 6, with a VLAN Name of Grey

2. The Forward Default VLAN Out All Ports is set to YES using the

Device/VLAN Configuration screen. This adds the Default VLAN to
the Port VLAN List of every switch port.

3. To allow all frames (except the AppleTalk frames, which will be

prevented in steps 4 and 5) from being transmitted out Port 1 to Switch
3 and the network backbone, Port VLAN IDs are assigned to all switch
ports using the Port Assignment screen, as follows:

• Port 1, VLAN ID: 5 for the Yellow VLAN

• Port 2, VLAN ID: 5 for the Yellow VLAN

• Port 3, VLAN ID: 5 for the Yellow VLAN

• Port 4, VLAN ID: 5 for the Yellow VLAN

• Port 5, VLAN ID: 5 for the Yellow VLAN

• Port 6, VLAN ID: 5 for the Yellow VLAN

• Port 7, VLAN ID: 5 for the Yellow VLAN

• Port 8, VLAN ID: 5 for the Yellow VLAN

4. On the Protocol VLAN Configuration screen, the VLAN ID 6 of the

Grey VLAN is assigned to the AppleTalk protocol.

• VLAN ID 6, Protocol Type: AppleTalk, Status: ADD

This creates the protocol VLAN ID 6 that will handle only AppleTalk
frames and enables ports to be assigned the this VLAN.

4-20 802.1Q VLAN User’s Guide

Example 4, Isolating Network Traffic According to Protocol

5. The AppleTalk frames must now be restricted to Ports 2 through 8 of

the Yellow VLAN. On the Protocol Ports Configuration screen, All
ports except Port 1 are assigned to the AppleTalk protocol, as follows:

• Port 2, VLAN ID: 6, Protocol: AppleTalk

• Port 3, VLAN ID: 6, Protocol: AppleTalk

• Port 4, VLAN ID: 6, Protocol: AppleTalk

• Port 5, VLAN ID: 6, Protocol: AppleTalk

• Port 6, VLAN ID: 6, Protocol: AppleTalk

• Port 7, VLAN ID: 6, Protocol: AppleTalk

• Port 8, VLAN ID: 6, Protocol: AppleTalk

Any AppleTalk frame received on ports 2 through 8 will be broadcast
to all other ports on Switch 5 associated with the AppleTalk protocol.
For example, if Port 2 received a frame with the AppleTalk protocol,
Switch 5 would only transmit the frame to Ports 2, 3, 4, 6, 7, and 8.

6. Use the VLAN Forwarding Configuration screen to assign Port 1 to

the Yellow VLAN and set the frame type to tagged. With this
configuration, the frames transmitted on Port 1 are tagged as being
from the Yellow VLAN.

If a frame associated with any protocol other than AppleTalk (for
example, for the mail server) is received on any of the Ports 2 through
8, the frame would be part of the Yellow VLAN and transmitted out
Port 1 as a tagged frame to Switch 3 and handled in the same manner
as previously described in the previous examples to route the frame to
the Mail Server on the first floor.

Any unicast frames received via Port 1 that are destined for a device
in the Yellow VLAN are transmitted to the correct device. Any
broadcast frames received via Port 1 are transmitted to all the devices
in the Yellow VLAN and handled in a similar manner as previously
described in Example 2.

802.1Q VLAN User’s Guide 4-21

Chapter 4: Examples

4-22 802.1Q VLAN User’s Guide

INDEX

Numerics

1D Trunk 1-6, 3-16, 4-10
1Q Trunk 1-5, 3-16, 4-4

C

Chapters

organization ix
Configuration 2-2
Conventions x

D

Default VLAN 1-5
Device VLAN Configuration screen

ADD/DEL (Toggle) 3-9

Admin Status (Toggle) 3-9

FID - lower part of screen

(Modifiable) 3-9

FID - upper part of screen

(Read-Only) 3-9

VLAN ID - lower part of screen

(Modifiable) 3-9

VLAN ID - upper part of screen

(Read-Only) 3-9

VLAN Name - lower part of screen

(Modifiable) 3-9

VLAN Out All Ports (Toggle) 3-9

E

Examples 4-1

F

FID. See Filtering Database ID
Filtering Database 1-5
Filtering Database ID 1-4
Forwarding list 1-5

adding entries 3-23

customizing 2-3

deleting entries 3-23

viewing 3-22
Forwarding mode

changing 3-13

Frame format

changing 3-24

Frames

tagged 1-5, 2-5
untagged 1-5, 2-4

H

Host data port 3-2, 3-3
Hybrid 3-15

I

Isolating Network Traffic According

to Protocol 4-17

L

Lists

Forwarding 1-5
Port VLAN 1-5

Local management. See managing the

switch

M

Managing the switch 3-1

when configured with VLANs 3-2
when not configured with

VLANs 3-1

N

Network Traffic

isolating 4-17

O

Organization of chapters ix
Other manuals x

802.1Q VLAN User’s Guide Index-1

Index

P

Port Assignment Configuration screen

FID (Read-Only) 3-15
Port Mode (Selectable) 3-15
VLAN ID (Selectable) 3-15
VLAN Name (Read-Only) 3-15

Port Filtering Configuration screen

Filter All Untagged Frames

(Toggle) 3-19

Filter Using VLAN Lists

(Toggle) 3-19

Port # (Selectable) 3-19
VLAN ID (Read-Only) 3-19
VLAN Name (Read-Only) 3-19

Port mode

1D Trunk 3-16
1Q Trunk 3-16
changing 3-15

Hybrid 3-15
Port VLAN list 1-5
Protocol

isolating network according to 4-17
Protocol Ports Configuration Screen

Current Ports - upper part of screen

(Read-Only) 3-32

DELETE ALL PORTS

(Selectable) 3-32

Port

(Selectable) 3-32

Port Type - upper part of screen

(Read-Only) 3-32
Priority (Read-Only) 3-32
Protocol (Read-Only) 3-32

Protocol VLAN Configuration

screen 3-24
Action (Toggle) 3-27
Configured Ports 3-26

Configured Ports BitMap - upper

part of screen

(Selectable) 3-26
Ether type (Modifiable) 3-28
Feature Status 3-27
Ports - upper part of screen

(Read-Only) 3-26
Protocol Type (Selectable) 3-27
VLAN ID - (Modifiable) 3-26
VLAN ID - upper part of screen

(Read-Only) 3-26

R

Related Documents x
Remote management. See managing

the switch

S

Screens

802.1Q VLAN Configuration Menu

screen 3-5
Device VLAN Configuration

screen 3-8
Port Assignment Configuration

screen 3-14
Port Filtering Configuration

screen 3-17
Protocol VLAN Configuration

screen 3-24
VLAN Forwarding Configuration

screen 3-21

Station 2-1
Switch 2-1

T

Tag 1-5
Tag Header 1-5
Tagged frame 1-5, 2-5

Index-2 802.1Q VLAN User’s Guide

U

Untagged frame 1-5, 2-4

V

VLAN

assigning ports 2-2
components 2-1
configuration 2-2
default VLAN 1-5
defining 2-2
definition 1-1 to 1-4
operation 2-3
terms 1-4
types 1-3

VLAN Configuration

deleting 3-12
disabling 3-12
enabling 3-12

VLAN Forwarding Configuration

screen
ADD/DELETE (Toggle) 3-22
Current VLAN Ports

(Read-Only) 3-22
Frame Format - upper part of screen

(Read-Only) 3-22
Frame Type- lower part of screen

(Toggle) 3-22
Port (Selectable) 3-22
Port Type (Read-Only) 3-22
VLAN ID (Selectable) 3-22
VLAN Name (Read-Only) 3-22

VLAN ID 1-4

assigning 3-16

VLAN Local Management 3-4
VLAN name 1-4

Index

802.1Q VLAN User’s Guide Index-3

Index

Index-4 802.1Q VLAN User’s Guide