Cisco IOS XR Interface and Hardware Component Configuration Guide, Release 3.2
Configuring VLAN Interfaces on Cisco IOS XR Software
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Configuring 802.1Q VLAN Interfaces on Cisco IOS XR Software

Table Of Contents

Configuring 802.1Q VLAN Interfaces on Cisco IOS XR Software

Contents

Prerequisites for Configuring 802.1Q VLAN Interfaces

Information About Configuring 802.1Q VLAN Interfaces

802.1Q VLAN Overview

802.1Q Tagged Frames

Subinterfaces

Subinterface MTU

Native VLAN

How to Configure 802.1Q VLAN Interfaces

Configuring 802.1Q VLAN Subinterfaces

Configuring Native VLAN

Removing an 802.1Q VLAN Subinterface

Configuration Examples for VLAN Interfaces

VLAN Subinterfaces: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance


Configuring 802.1Q VLAN Interfaces on Cisco IOS XR Software


This module describes the configuration and management of 802.1Q VLAN interfaces on routers supporting Cisco IOS XR software.

The IEEE 802.1Q specification establishes a standard method for tagging Ethernet frames with VLAN membership information, and defines the operation of VLAN bridges that permit the definition, operation, and administration of VLAN topologies within a bridged LAN infrastructure.

The 802.1Q standard is intended to address the problem of how to break large networks into smaller parts so broadcast and multicast traffic does not use more bandwidth than necessary. The standard also helps provide a higher level of security between segments of internal networks.

Feature History for Configuring 802.1Q VLAN Interfaces on Cisco IOS XR Software

Release
Modification

Release 3.0

This feature was introduced.

Release 3.2

This feature was first supported on the Cisco XR 12000 Series Router.


Contents

Prerequisites for Configuring 802.1Q VLAN Interfaces

Information About Configuring 802.1Q VLAN Interfaces

How to Configure 802.1Q VLAN Interfaces

Configuration Examples for VLAN Interfaces

Additional References

Prerequisites for Configuring 802.1Q VLAN Interfaces

Before configuring 802.1Q VLAN interfaces, be sure that the following conditions are met:

You must be in a user group associated with a task group that includes the proper task IDs for VLAN commands.

Task IDs for commands are listed in the Cisco IOS XR Task ID Reference Guide.

You must have a configured Ethernet interface. See the
Configuring Ethernet Interfaces on Cisco IOS XR Software module in this book.

Information About Configuring 802.1Q VLAN Interfaces

To configure 802.1Q VLAN interfaces, you need to understand the following concepts:

802.1Q VLAN Overview

802.1Q Tagged Frames

Subinterfaces

Subinterface MTU

Native VLAN

802.1Q VLAN Overview

A VLAN is a group of devices on one or more LANs that are configured so that they can communicate as if they were attached to the same wire, when in fact they are located on a number of different LAN segments. Because VLANs are based on logical instead of physical connections, they are very flexible for user and host management, bandwidth allocation, and resource optimization.

The IEEE 802.1Q protocol standard addresses the problem of breaking large networks into smaller parts so broadcast and multicast traffic does not consume more bandwidth than necessary. The standard also helps provide a higher level of security between segments of internal networks.

The 802.1Q specification establishes a standard method for inserting VLAN membership information into Ethernet frames.

802.1Q Tagged Frames

The IEEE 802.1Q tag-based VLAN uses an extra tag in the MAC header to identify the VLAN membership of a frame across bridges. This tag is used for VLAN and quality of service (QoS) priority identification. The VLANs can be created statically by manual entry or dynamically through Generic Attribute Registration Protocol (GARP) VLAN Registration Protocol (GVRP). The VLAN ID associates a frame with a specific VLAN and provides the information that switches need to process the frame across the network. A tagged frame is four bytes longer than an untagged frame and contains two bytes of Tag Protocol Identifier (TPID) residing within the type and length field of the Ethernet frame and two bytes of Tag Control Information (TCI) which starts after the source address field of the Ethernet frame.

Subinterfaces

Subinterfaces are logical interfaces created on a hardware interface. These software-defined interfaces allow for segregation of traffic into separate logical channels on a single hardware interface as well as allowing for better utilization of the available bandwidth on the physical interface.

Subinterfaces are distinguished from one another by adding an extension on the end of the interface name and designation. For instance, the Ethernet subinterface 23 on the physical interface designated TenGigE 0/1/0/0 would be indicated by TenGigE 0/1/0/0.23.

Before a subinterface is allowed to pass traffic it must have a valid tagging protocol encapsulation and VLAN identifier assigned. All Ethernet subinterfaces always default to the 802.1Q VLAN encapsulation. However, the VLAN identifier must be explicitly defined.

Subinterface MTU

The subinterface MTU is inherited from the physical interface with an additional four bytes allowed for the 802.1Q VLAN tag.

Native VLAN

Each physical port may have a native VLAN assigned. All untagged frames are assigned to the LAN specified in the PVID parameter. When a tagged frame is received by a port, the tag is respected. If the frame is untagged, the value contained in the PVID is considered as a tag. Because the frame is untagged and the PVID is tagged, native VLAN allows the coexistence of VLAN-aware bridge or stations with VLAN-unaware bridges or stations.

How to Configure 802.1Q VLAN Interfaces

This section contains the following procedures:

Configuring 802.1Q VLAN Subinterfaces (Required)

Configuring Native VLAN (Required)

Removing an 802.1Q VLAN Subinterface (Required)

Configuring 802.1Q VLAN Subinterfaces

This task explains how to configure 802.1Q VLAN subinterfaces. To remove these subinterfaces, see the" Removing an 802.1Q VLAN Subinterface" section of this module.

SUMMARY STEPS

1. configure

2. interface type instance

3. dot1q vlan number

4. ipv4 address ip-address

5. exit

6. Repeat Step 2 through Step 5 to define the rest of the VLAN subinterfaces.

7. end
or
commit

8. show vlan interface [type instance] [location node-id]

9. show vlan trunks [brief | summary] [location node-id] [interface type instance]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

configure

Example:

RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2 

interface type instance

Example:

RP/0/RP0/CPU0:router(config)# interface TenGigE 0/2/0/4.10

Enters subinterface configuration mode and specifies the interface type, location, and subinterface number.

Range is from 0 to 4095.

Step 3 

dot1q vlan number

Example:

RP/0/RP0/CPU0:router(config-subif)# dot1q vlan 100

Assigns a VLAN to the subinterface.

Step 4 

ipv4 address ip-address

Example:

RP/0/RP0/CPU0:router(config-subif)# ipv4 address 178.18.169.23/24

Assigns an IP address and subnet mask to the interface.

Step 5 

exit

Example:

RP/0/RP0/CPU0:router(config-subif)# exit

(Optional) Exits the subinterface configuration mode.

The exit command is not explicitly required.

Step 6 

Repeat Step 2 through Step 5 to define the rest of the VLAN subinterfaces.

Step 7 

end

or

commit

Example:

RP/0/0/CPU0:router(config)# end

or

RP/0/0/CPU0:router(config)# commit

Saves configuration changes.

When you issue the end command, the system prompts you to commit changes:

Uncommitted changes found, commit them before  
exiting(yes/no/cancel)? 
[cancel]:
 
        

Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 8 

show vlan interface [type instance][location node-id]

Example:

RP/0/RP0/CPU0:router# show vlan interface 5

(Optional) Displays the interface configuration.

To display the configuration for a slot, use the location keyword.

To display the configuration for the specified interface or subinterface, use the interface keyword .

Step 9 

show vlan trunks [brief | summary][location node-id][interface type instance]

Example:

RP/0/RP0/CPU0:router# show vlan trunk summary

(Optional) Displays summary information about each of the VLAN trunk interfaces.

The keywords have the following meanings:

briefDisplays a brief summary.

summaryDisplays a full summary.

location Displays information about the VLAN trunk interface on the given slot.

interfaceDisplays information about the specified interface or subinterface.

Configuring Native VLAN

This task explains how to configure the native, or default, VLAN on an interface.


Note This task is not available on the Cisco XR 12000 Series Router.


SUMMARY STEPS

1. configure

2. interface type instance

3. dot1q native vlan number

4. end
or
commit

5. show vlan trunks [brief | summary] [location node-id] [interface type instance]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

configure

Example:

RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2 

interface type instance

Example:

RP/0/RP0/CPU0:router(config)# interface TenGigE 0/2/0/4

Enters interface configuration mode and specifies the 10-Gigabit Ethernet interface name and designation.

Step 3 

dot1q native vlan number

Example:

RP/0/RP0/CPU0:router(config-if)# dot1q native vlan 1

Defines the default, or Native VLAN, associated with an 802.1Q trunk interface.

The number argument is the ID of the trunk interface.

Range is from 1 to 4094 inclusive (0 and 4095 are reserved).

Step 4 

end

or

commit

Example:

RP/0/0/CPU0:router(config-if)# end

or

RP/0/0/CPU0:router(config-if)# commit

Saves configuration changes.

When you issue the end command, the system prompts you to commit changes:

Uncommitted changes found, commit them before  
exiting(yes/no/cancel)? 
[cancel]:
 
        

Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 5 

show vlan trunks [brief | summary][location node-id][interface type instance]

Example:

RP/0/RP0/CPU0:router# show vlan trunk summary

(Optional) Displays summary information about each of the VLAN trunk interfaces.

The keywords have the following meanings:

brief—Displays a brief summary.

summary—Displays a full summary.

location— Displays information about the VLAN trunk interface on the given slot.

interface—Displays information about the specified interface or subinterface.

Removing an 802.1Q VLAN Subinterface

This task explains how to remove 802.1Q VLAN subinterfaces that have been previously configured using the "Configuring 802.1Q VLAN Subinterfaces" task in this module.

SUMMARY STEPS

1. configure

2. no interface type instance

3. Repeat Step 2 to remove other VLAN subinterfaces.

4. end
or
commit

5. show vlan interface [type instance] [location node-id]

6. show vlan trunks [brief | summary] [location node-id] [interface type instance]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

configure

Example:

RP/0/RP0/CPU0:router# configure

Enters global configuration mode.

Step 2 

no interface type instance

Example:

RP/0/RP0/CPU0:router(config)# no interface TenGigE 0/2/0/4.10

Removes the subinterface, which also automatically deletes all the configuration applied to the subinterface.

The instance argument is the name of the subinterface to be deleted.

Step 3 

Repeat step 2 to remove other VLAN subinterfaces.

Step 4 

end

or

commit

Example:

RP/0/0/CPU0:router(config)# end

or

RP/0/0/CPU0:router(config)# commit

Saves configuration changes.

When you issue the end command, the system prompts you to commit changes:

Uncommitted changes found, commit them before  
exiting(yes/no/cancel)? 
[cancel]:
 
        

Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.

Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.

Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.

Use the commit command to save the configuration changes to the running configuration file and remain within the configuration session.

Step 5 

show vlan interface [type instance][location node-id]

Example:

RP/0/RP0/CPU0:router# show vlan interface 5

(Optional) Displays the interface configuration.

To display the configuration for a slot, use the location keyword.

To display the configuration for the specified interface or subinterface, use the interface keyword .

Step 6 

show vlan trunks [brief | summary][location node-id][interface type instance]

Example:

RP/0/RP0/CPU0:router# show vlan trunk summary

(Optional) Displays summary information about each of the VLAN trunk interfaces.

The keywords have the following meanings:

brief—Displays a brief summary.

summary—Displays a full summary.

location— Displays information about the VLAN trunk interface on the given slot.

interface—Displays information about the specified interface or subinterface.

Configuration Examples for VLAN Interfaces

This section contains the following example:

VLAN Subinterfaces: Example

VLAN Subinterfaces: Example

Following is a comprehensive example for creating three VLAN subinterfaces at one time:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface TenGigE 0/2/0/4.1 
RP/0/RP0/CPU0:router(config-subif)# dot1q vlan 10
RP/0/RP0/CPU0:router(config-subif)# ipv4 address 10.0.10.1/24
RP/0/RP0/CPU0:router(config-subif)# interface TenGigE0/2/0/4.2 
RP/0/RP0/CPU0:router(config-subif)# dot1q vlan 20
RP/0/RP0/CPU0:router(config-subif)# ipv4 address 10.0.20.1/24 
RP/0/RP0/CPU0:router(config-subif)# interface TenGigE0/2/0/4.3 
RP/0/RP0/CPU0:router(config-subif)# dot1q vlan 30
RP/0/RP0/CPU0:router(config-subif)# ipv4 address 10.0.30.1/24 
RP/0/RP0/CPU0:router(config-subif)# commit
 
   
RP/0/RP0/CPU0Sep 19 20:15:58.925 : config[65726]: %LIBTARCFG-6-COMMIT : Configur
ation committed by user 'unknown'.   Use 'show commit changes 1000003460' to view th
e changes.
RP/0/RP0/CPU0:router(config-subif)# exit
RP/0/RP0/CPU0:router(config)# exit
 
   
RP/0/RP0/CPU0:router# show vlan trunks summary 
VLAN trunks: 1,
  1 are 802.1Q (Ether).
Sub-interfaces: 3,
  3 are up.
802.1Q VLANs: 3,
  3 have VLAN Ids.
 
   
RP/0/RP0/CPU0:router# show vlan interface
interface           encapsulation  vlan-id  intf-state
Te0/2/0/4.1         802.1Q              10  up
Te0/2/0/4.2         802.1Q              20  up
Te0/2/0/4.3         802.1Q              30  up
RP/0/RP0/CPU0:router# show vlan trunks brief
interface           encapsulations        intf-state
Te0/2/0/4           802.1Q (Ether)        up
 
   

Additional References

The following sections provide references related to VLAN interface configuration.

Related Documents

Related Topic
Document Title

Cisco IOS XR master command reference

Cisco IOS XR Master Commands List, Release 3.2

Cisco IOS XR interface configuration commands

Cisco CRS-1 Series Interface and Hardware Component Command Reference

Initial system bootup and configuration information for a router using the Cisco IOS XR Software.

Cisco IOS XR Getting Started Guide

Information about user groups and task IDs

Cisco IOS XR Task ID Reference Guide

Information about configuring interfaces and other components on the Cisco CRS-1 from a remote Craft Works Interface (CWI) client management application

Cisco CRS-1 Series Carrier Routing System Craft Works Interface Configuration Guide


Standards

Standards
Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature


MIBs

MIBs
MIBs Link

There are no applicable MIBs for this module.

To locate and download MIBs for selected platforms using
Cisco IOS XR Software, use the Cisco MIB Locator found at the following URL:

http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml


RFCs

RFCs
Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.


Technical Assistance

Description
Link

The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/techsupport