Configuring EVPN-VPWS over SRv6 with Traffic Engineering

Starting in Junos OS Evolved 25.2R1, the ACX Series routers support EVPN-VPWS over SRv6 traffic engineering (TE) tunnels with fallback capability. While EVPN services themselves do not support the fallback switchover of routes, you can configure segment routing policies to define a secondary route. If the primary path becomes unavailable, the device automatically switches to the secondary route as a backup.

To configure EVPN-VPWS over SRv6 TE routes, you must define SRv6 TE routes and their associated transport classes. When SRv6 TE is configured with a color (transport class), the resulting route is installed in the colored routing table rti-tc-<color>.inet6.3. This is referred to as the intent route. The associated locator prefix route is installed in the default table inet6.3 and is known as the non-intent route or best-effort route.

By utilizing SRv6 TE routes, you can ensure that intended routes with lower metrics are prioritized while maintaining best-effort routes as fallback options. This ensures that your primary routes are optimized for performance, and in the event of a failure, there is an automatic switch to the best-effort routes to maintain service continuity.

By default, Junos OS Evolved enables fallback to best-effort routes for auto-created transport classes. To configure TE routes without fallback, you must run the CLI command set protocols sr-te transport-class fallback none at the top of the hierarchy. This command ensures that only the preferred TE routes are utilized where best-effort routes are not acceptable.

Junos OS Evolved supports both single-homing and multi-homing networks for these services.

Figure 1: EVPN-VPWS SRTE topology

In Figure 1, we have a topology with two possible paths from CE1 to CE4. The basic steps for configuring EVPN-VPWS over SRv6 with traffic engineering on the ingress device (PE1) is as follow.

1. Configure the node locator SID within the IS-IS protocol.

2. Configure EVPN-VPWS services.

3. Configure support for micro-SID and SRv6.

4. Define the transport class at the ingress or egress node. For this example, we define a gold transport class and assign community value.

5. Configure import or export policies to route traffic. For this example, we use an export policy.

6. Configure source path route to the remote device and the hops for the primary and secondary paths.

   Note:

   Use the loopback address of the remote device for the tunnel endpoint.