Configuring EVPN Active-Standby Multihoming to a Single PE Device
You can configure EVPN active-standby multihoming on a single PE device by configuring a standby (protect) interface to provide redundancy to an active (protected) interface. Figure 1 illustrates an EVPN topology with active-standby multihoming to a single PE device. A protect interface provides the benefit of a backup for the protected primary interface in case of failure. The PE device uses the primary interface for network traffic while the primary interface is functioning. If the primary interface fails, the protect interface becomes active and traffic switches to the protect interface. When the primary interface returns, the primary interface becomes the active interface once again.
If connectivity fault management (CFM) is enabled, the protect interface will trigger CFM to send Type, Length, and Value (TLV) or Remote Defect Indication (RDI) interface status to the customer edge device
Junos OS does not support the protect interface in the following cases:
On an interface that has been configured as an ESI in EVPN multihoming
To configure the protect interface in a routing instance, configure both the protect interface and the primary interface in the routing instance for EVPN and include the protect-interface statement in the primary interface hierarchy.
To configure the protect interface in a routing instance, configure both the protect interface and the primary interface in the routing instance for EVPN-VPWS and include the protect-interface statement in the evpn protocol hierarchy.
To configure the protect interface in a bridge domain, configure both the protect interface and the primary interface in the bridge domain and include the protect-interface statement in the primary interface hierarchy.
To display the protect interface, use the show evpn instance extensive operational command.
user@PE1> show evpn instance extensive
Instance: blue Route Distinguisher: 10.255.255.1:100 Per-instance MAC route label: 299776 MAC database status Local Remote MAC advertisements: 0 0 MAC+IP advertisements: 0 0 Default gateway MAC advertisements: 0 0 Number of local interfaces: 5 (5 up) Interface name ESI Mode Status AC-Role ae0.0 00:11:22:33:44:55:66:77:88:99 all-active Up Root ge-0/0/3.0 00:00:00:00:00:00:00:00:00:00 single-homed Up Root ge-0/0/4.0 00:11:11:11:44:55:66:77:88:99 all-active Up Root ge-0/0/4.1 00:22:22:22:44:55:66:77:88:99 all-active Up Root ge-0/0/4.50 00:00:00:00:00:00:00:00:00:00 single-homed Up Root Number of IRB interfaces: 1 (0 up) Interface name VLAN VNI Status L3 context irb.1 25 Down vrf Number of protect interfaces: 1 Interface name Protect Interface name Status ge-0/0/3.1 ge-0/0/4.50 Protect-inactive
The show interfaces detail command shows that the protect interface has a CCC-DOWN status
user@PE1> show interfaces ae0.0 detail
Logical interface ae80.0 (Index 399) (SNMP ifIndex 612) (Generation 223) Flags: Up SNMP-Traps CCC-Down 0x20004000 VLAN-Tag [ 0x8100.10 ] Encapsulation: VLAN-Bridge Statistics Packets pps Bytes bps Bundle: Input : 0 0 0 0 Output: 0 0 0 0 Adaptive Statistics: Adaptive Adjusts: 0 Adaptive Scans : 0 Adaptive Updates: 0 Link: ge-0/1/8.0 Input : 0 0 0 0 Output: 0 0 0 0 Aggregate member links: 1 Marker Statistics: Marker Rx Resp Tx Unknown Rx Illegal Rx ge-0/1/8.0 0 0 0 0 Protocol bridge, MTU: 1522, Generation: 263, Route table: 11, Mesh Group: __all_ces__