L3VPN Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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L3VPN Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

Configure Layer 3 route synchronization with port-active redundancy

Updated: June 17, 2026

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Provides instructions to configure Layer 3 route synchronization with port-active redundancy, enabling reliable failover and efficient routing in EVPN multihoming scenarios.

Enable consistent Layer 3 route synchronization for VRF instances across redundant PE routers in EVPN fabric with port-active multihoming.

Port-active mode ensures that only a single PE forwards traffic for a given Ethernet segment at any time, improving network redundancy and reliability.

Before you begin

  • Ensure you have access to the command-line interface (CLI) of the PE router.

  • Identify the VRF instances for which you want to enable Layer 3 route synchronization.

  • Determine the interfaces that will participate in port-active multihoming.

Procedure

1.

Configure the BGP route-targets for VRFs to control IPv4/IPv6 route distribution and enable synchronization of Layer 3 routing information with the Layer-2 EVPN fabric.

Example:

Router# configure
Router(config)#vrf PA1
Router(config-vrf)#address-family ipv4 Unicast
Router(config-vrf-af)#import route-target 64600:10000
Router(config-vrf-af)#export route-target 64600:10000
Router(config-vrf-af)#evpn-route-sync 10000
Router(config-vrf)#vrf PA1
Router(config-vrf)#address-family ipv6 Unicast
Router(config-vrf-af)#import route-target 64600:10000
Router(config-vrf-af)#export route-target 64600:10000
Router(config-vrf)#vrf PA2
Router(config-vrf)#address-family ipv4 Unicast
Router(config-vrf-af)#import route-target 64600:10001
Router(config-vrf-af)#export route-target 64600:10001
Router(config-vrf-af)#evpn-route-sync 10001
Router(config-vrf)#vrf PA2
Router(config-vrf)#address-family ipv6 Unicast
Router(config-vrf-af)#import route-target 64600:10001
Router(config-vrf-af)#export route-target 64600:10001
Router(config-vrf-af)#commit
Router(config-vrf-af)#exit
Router(config-vrf)#exit
2.

Configure VRF, encapsulation, and L3 addresses for the relevant subinterfaces.

Example:

Router(config)#interface Bundle-Ether200.2307
Router(config-subif)#vrf PA1
Router(config-subif)#ipv4 address 172.16.1.1/24
Router(config-subif)#ipv6 address 155:1:1:7::1/64
Router(config-subif)#encapsulation dot1q 2307
3.

Configure Ethernet segment for port-active redundancy.

Example:

Router(config)# evpn
Router(config-evpn)# interface Bundle-Ether200
Router(config-evpn-ac)# ethernet-segment
Router(config-evpn-ac-es)# identifier type 0 11.11.11.11.11.11.11.11.11
Router(config-evpn-ac-es)# load-balancing-mode port-active
Router(config-evpn-ac-es)# root
Router(config)# commit
4.

Use the show arp vrf PA1 detail command to verify the ARP entries and their synchronization status for VRF PA1.

Example:

Router#show arp vrf PA1 detail

-------------------------------------------------------------------------------
0/RP0/CPU0
-------------------------------------------------------------------------------
Address         Age        Hardware Addr   State      Flag       Type  Interface
192.0.2.11       -          0000.0000.0200  Interface  Unknown    ARPA  Bundle-Ether200.2301
192.0.2.12      -          0010.9400.2f8e  EVPN_SYNC  EVPN-SYNC  ARPA  Bundle-Ether200.2301
192.0.2.13       -          0000.0000.0200  Interface  Unknown    ARPA  Bundle-Ether200.2303
192.0.2.14      00:00:36   0010.9400.2f90  Dynamic    Dynamic    ARPA  Bundle-Ether200.2303
192.0.2.15       -          0000.0000.0200  Interface  Unknown    ARPA  Bundle-Ether200.2305
192.0.2.16      00:00:36   0010.9400.2f92  Dynamic    Dynamic    ARPA  Bundle-Ether200.2305
192.0.2.17       -          0000.0000.0200  Interface  Unknown    ARPA  Bundle-Ether200.2307
192.0.2.18      -          0010.9400.2f94  EVPN_SYNC  EVPN-SYNC  ARPA  Bundle-Ether200.2307
5.

Verify route synchronization status for the bridge-domain.

Example:

Router# show l2vpn bridge-domain bd-name rs#10000 detail

Legend: pp = Partially Programmed.
Bridge group: #ROUTE-SYNC, bridge-domain: rs#10000, id: 140, state: up, ShgId: 0, MSTi: 0
  Coupled state: disabled
  VINE state: EVPN Native
  MAC learning: enabled
  MAC withdraw: enabled
    MAC withdraw for Access PW: enabled
    MAC withdraw sent on: bridge port up
    MAC withdraw relaying (access to access): disabled
  Flooding:
    Broadcast & Multicast: enabled
    Unknown unicast: enabled
  MAC aging time: 300 s, Type: inactivity
  MAC limit: 524287, Action: none, Notification: syslog
  MAC limit reached: no, threshold: 75%
  MAC port down flush: enabled
  MAC Secure: disabled, Logging: disabled
  Split Horizon Group: none
  E-Tree: Root
  Dynamic ARP Inspection: disabled, Logging: disabled
  IP Source Guard: disabled, Logging: disabled
  DHCPv4 Snooping: disabled
  DHCPv4 Snooping profile: none
  IGMP Snooping: disabled
  IGMP Snooping profile: none
  MLD Snooping profile: none
  Storm Control: disabled
  Bridge MTU: 1500
  MIB cvplsConfigIndex: 141
  Filter MAC addresses:
  P2MP PW: disabled
  Multicast Source: Not Set
  Create time: 11/06/2025 03:28:06 (00:05:13 ago)
  No status change since creation
  ACs: 0 (0 up), VFIs: 0, PWs: 0 (0 up), PBBs: 0 (0 up), VNIs: 0 (0 up)
  List of EVPNs:
    EVPN, state: unresolved
      evi: 0 (N/A)
      XC ID 0x0
  List of ACs:
  List of Access PWs:
  List of VFIs:
  List of Access VFIs:
6.

Verify EVPN EVI details, including its association with VRF for route synchronization.

Example:

Router# show evpn evi vpn-id 10001 detail 

VPN-ID     Encap      Bridge Domain                Type
---------- ---------- ---------------------------- -------------------
10001      ROUTE-SYNC rs#10001                     EVPN
   Stitching: Regular
   E-Tree: Root
   Forward-class: 0
   Advertise MACs: No
   Advertise BVI MACs: No
   Aliasing: Enabled
   UUF: Enabled
   Re-origination: Enabled
   Multicast:
     IGMP-Snooping Proxy: No
     MLD-Snooping Proxy : No
   BGP Implicit Import: Enabled
   VRF Name: PA2
   Preferred Nexthop Mode: Off
   BVI Coupled Mode: No
   BVI Subnet Withheld: ipv4 No, ipv6 No
   L3VRF Label Mode: Per-VRF
   RD Config: none
   RD Auto  : (auto) 192.168.10.1:10001
   RT Auto  : 64600:10001
   Route Targets in Use           Type
   ------------------------------ ---------------------
   64600:10001                    Import
   64600:10001                    Export
7.

Use the show evpn ethernet-segment interface BE200 command to check the load-balancing mode.

Example:

Router# show evpn ethernet-segment interface BE200 carving detail
..

Ethernet Segment Id      Interface                          Originating IP
------------------------ ---------------------------------- --------------------
0011.1111.1111.1111.1111 BE200                              192.168.10.1
                                                            192.168.20.1
  ES to BGP Gates   : Ready
  ES to L2FIB Gates : Ready
  Main port         :
     Interface name : Bundle-Ether200
     Interface MAC  : 0000.0000.0200
     IfHandle       : 0x78000234
     State          : Standby
     Redundancy     : Not Defined
  ESI ID            : 1
  ESI type          : 0
     Value          : 0011.1111.1111.1111.1111
  ES Import RT      : 1111.1111.1111 (Local)
  Topology          :
     Operational    : MH
     Configured     : Port-Active
  Service Carving   : Auto-selection
     Multicast      : Disabled
  Convergence       : Reroute
  Peering Details   : 2 Nexthops
     192.168.10.1 [MOD:P:00:T]
     192.168.20.1 [MOD:P:00:T]

Layer 3 route synchronization is successfully configured and verified, ensuring consistent routing information and L2VPN connectivity across the EVPN fabric for VRFs PA1 and PA2.