Interfaces and Hardware Component Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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Interfaces and Hardware Component Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

IRB configuration examples

Updated: July 31, 2026

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This topic covers various configuration examples for IRB.

Basic IRB configuration

This example shows how to perform the most basic IRB configuration:


! Configure the BVI and its IPv4 address
!
Router#configure
Router(config)#interface bvi 1
Router(config-if))#ipv4 address 10.10.0.4 255.255.255.0
Router(config-if))#exit
!
! Configure the Layer 2 AC interface
!
Router(config)#interface HundregGigE 0/1/0/0 l2transport
Router(config-if))#exit
!
! Configure the L2VPN bridge group and bridge domain and assign interfaces
!
Router(config)#l2vpn
Router(config-l2vpn)#bridge group 10
Router(config-l2vpn-bg)#bridge-domain 1
Router(config-l2vpn-bg-bd)#interface HundregGigE 0/1/0/0
Router(config-l2vpn-bg-bd-if)#exit
!
! Associate a BVI to the bridge domain
!
Router(config-l2vpn-bg-bd)#routed interface bvi 1
Router(config-l2vpn-bg-bd)#commit

IRB using ACs with VLANs

This example shows how to configure IRB on a bridge domain with Layer 2 ACs using 802.1Q-encapsulated VLANs:


! Configure the BVI and its IPv4 address
!
Router#configure
Router(config)#interface bvi 1
Router(config-if))#ipv4 address 10.10.0.4 255.255.255.0
Router(config-if))#exit
!
! Configure the Layer 2 AC interfaces using dot1q encapsulation on a VLAN
!
Router(config)#interface HundredGigE 0/1/0/0.1 l2transport
Router(config-if))#no ip address
Router(config-if))#encapsulation dot1q 1 exact
Router(config-if))#rewrite ingress tag pop 1 symmetric
Router(config-if))#exit
Router(config)#interface HundredGigE 0/1/0/1.1 l2transport
Router(config-if))#no ip address
Router(config-if))#encapsulation dot1q 1 exact
Router(config-if))#rewrite ingress tag pop 1 symmetric
Router(config-if))#exit
!
! Configure the L2VPN bridge group and bridge domain and assign interfaces
!

Router(config)#l2vpn
Router(config-l2vpn)#bridge group 10
Router(config-l2vpn-bg)#bridge-domain 1
Router(config-l2vpn-bg-bd)#interface HundredGigE 0/1/0/0.1
Router(config-l2vpn-bg-bd)#interface HundredGigE 0/1/0/1.1
Router(config-l2vpn-bg-bd-if)#exit
!
! Associate a BVI to the bridge domain
!
Router(config-l2vpn-bg-bd)#routed interface bvi 1
Router(config-l2vpn-bg-bd)#commit

IPv4 addressing on a BVI supporting multiple IP networks

This example shows how to configure secondary IPv4 addresses on a BVI that supports bridge domains for the 10.10.10.0/24, 10.20.20.0/24, and 10.30.30.0/24 networks. In this example, the BVI must have an address on each of the bridge domain networks:


Router#configure
Router(config)#interface bvi 1
Router(config-if))#ipv4 address 10.10.10.4 255.255.255.0
Router(config-if))#ipv4 address 10.20.20.4 255.255.255.0 secondary
Router(config-if))#ipv4 address 10.30.30.4 255.255.255.0 secondary
Router(config-if))#commit

Comprehensive IRB configuration with BVI bundle interfaces and multicast configuration

This example shows a more comprehensive router configuration with IRB and BVI multicast support:


interface Bundle-Ether25
 ipv4 address 10.21.0.2 255.255.255.0
!
interface Loopback0
 ipv4 address 10.5.5.5 255.255.255.255
!
interface HundredGigE0/0/0/1
 negotiation auto
!
interface HundredGigE0/0/0/1.1 l2transport
 encapsulation dot1q 1
 rewrite ingress tag pop 1 symmetric
!
interface HundredGigE0/0/0/1.2 l2transport
 encapsulation dot1q 2
 rewrite ingress tag pop 1 symmetric
!

interface HundredGigE0/0/0/9
 bundle id 25 mode active
!
interface HundredGigE0/0/0/19
 bundle id 25 mode active
!
interface HundredGigE0/0/0/29
 bundle id 25 mode active
!

interface HundredGigE0/0/0/39
 bundle id 25 mode active

interface BVI1
 ipv4 address 10.1.1.1 255.255.255.0
!
interface BVI2
 ipv4 address 10.1.2.1 255.255.255.0

router ospf 100
 router-id 10.5.5.5
 area 0
  interface Bundle-Ether25
    interface Loopback0
    interface BVI1
   interface BVI2
  !
l2vpn
 bridge group IRB
  bridge-domain IRB1
   igmp snooping profile IRB_SNOOP
   interface HundredGigE0/0/0/1.1
   !
   routed interface BVI1
  !
  bridge-domain IRB2
   igmp snooping profile IRB_SNOOP
   interface HundredGigE0/0/0/1.2
   !
   routed interface BVI2

multicast-routing
 address-family ipv4
  interface all enable
igmp snooping profile IRB_SNOOP
 report-suppression disable
!
router pim
 address-family ipv4
  rp-address 10.10.10.10

IRB with BVI and VRRP configuration

This example shows a partial router configuration for the relevant configuration areas for IRB support of a BVI and VRRP:

Note

VRRPv6 is also supported.


l2vpn
 bridge group IRB
  bridge-domain IRB-EDGE
   interface HundredGigE0/0/0/8
!
   routed interface BVI 100
!
interface HundredGigE0/0/0/8
  l2transport
!
interface BVI 100
 ipv4 address 10.21.1.1 255.255.255.0
!
router vrrp
 interface BVI 100
  vrrp 1 ipv4 10.21.1.100
  vrrp 1 priority 100
 !

6PE or 6VPE with BVI configuration

This example shows how to configure an MPLS 6PE/6VPE environment using BVIs at the CE-facing sides of the Cisco 8000 Series Router as the PE devices.

This figure shows the location of the BVI interfaces (green icons) on the Cisco 8000 Series Routers as the PE1 and PE2 devices.

Figure 1. BVI interfaces on the CE-facing sides in an MPLS 6PE or 6VPE network

This is a sample configuration only for the Cisco 8000 Series Router (PE1) device with a BVI interface numbered 1 on the CE-facing side, and a non-BVI interface (HundredGigE 0/1/0/37) on the core-facing side. A similar configuration would apply to the PE2 device:


! Be sure to configure IPv6 unicast address families
!
vrf 1
address-family ipv6 unicast
  import route-target
   100:2
  export route-target
   100:2

interface Loopback0
 ipv4 address 10.11.11.11/32
!
! Configure the BVI interface to participate in the VRF
! and with an IPv6 address.
!
interface BVI1
 vrf 1
 ipv6 address 2001:DB8:1/32
!
! Assign the Ethernet CE-facing interface to the
! L2VPn bridge domain where the routed BVI interface is also associated.
!
l2vpn
 bridge group 1
  bridge-domain 1
   interface HundredGigE 0/1/0/11
 routed interface BVI1
!
! Configure OSPF routing for the BVI interface for
! advertisement of its IPv6 address.
!
router ospfv3 1
 graceful-restart
 redistribute bgp 1
 area 1
  interface BVI1
  interface Loopback0
!
! Configure BGP routing and be sure to specify the
! IPv6 unicast address family.
! Note that the per-VRF label allocation mode is required
! and is the only supported label allocation mode.
!
router bgp 1
 bgp router-id 10.11.11.11
 bgp redistribute-internal
 bgp graceful-restart

 address-family ipv6 unicast
  redistribute ospfv3 1 match internal external
  label-allocation-mode per-vrf
  allocate-label all
 !
 address-family vpnv6 unicast
 !
 neighbor 10.11.12.12
  remote-as 1
  update-source Loopback0
  address-family ipv6 unicast
   route-policy pass-all in
   route-policy pass-all out
  !
  address-family ipv6 labeled-unicast
  !
  address-family vpnv6 unicast
   route-policy pass-all in
   route-policy pass-all out
  !
 vrf 1
  rd 100:2
 label-allocation-mode per-vrf
  address-family ipv6 unicast
   redistribute connected

mpls ldp
 router-id 10.11.11.11
 graceful-restart
 interface HundredGigE 0/1/0/37

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