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
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Ensure you have access to the command-line interface (CLI) of the PE router.
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Identify the VRF instances for which you want to enable Layer 3 route synchronization.
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Determine the interfaces that will participate in port-active multihoming.
Procedure
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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 -
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 -
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 -
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 -
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: -
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 -
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.