Cisco ASR 9000 Series

Topology
Figure 86: EVPN VPWS Preferred Path over SR-TE Policy
Consider a topology where PE1 and PE3 are the two EVPN VPWS PW end-points. Traffic is sent from PE1
to PE3 through SR in the core. Traffic from PE1 can be sent to PE3 either through P1 or P2 node. In this
example, the EVPN VPWS preferred path over SR policy is configured to show the traffic flow from PE1 to
PE3 using prefix-SID. Using adjacency-SID, you can steer traffic flow from PE1 to PE3 and specify whether
it should pass through P1 or P2 node.
Configure EVPN VPWS Preferred Path over SR-TE Policy
You must complete these tasks to ensure the successful configuration of EVPN VPWS Preferred Path over
SR-TE Policy feature:
• Configure Prefix-SID in ISIS
• Configure Adjacency-SID in ISIS
• Configure segment-list
• Configure SR-TE policy
• Configure EVPN VPWS over SR-TE policy
• Configure VPWS pseudowire headend over SR-TE policy
Configure Prefix-SID in ISIS
Configure Prefix-SID on PE1, P1, P2, and PE3.
/* Configure Prefix-SID on PE1 */
Router# configure
Router(config)# segment-routing
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
621
L2VPN Services over Segment Routing for Traffic Engineering Policy
Configure EVPN VPWS Preferred Path over SR-TE Policy