Service Path Preference For L2Vpn; Understanding How Service Path Preference Works - Cisco ASR 9000 Series Configuration Manuallines

Implementing Multipoint Layer 2 Services
Figure 23: NLRI and Extended Communities

Service Path Preference for L2VPN

Service Path Preference feature (SPP) helps control transport path for L2VPN services in traffic engineering
(TE) tunnels. SPP feature provides a way for services to influence path selection while forwarding in
Multiprotocol Label Switching (MPLS) networks. SPP is achieved by associating a control plane policy with
a forward-class. SPP is supported for per-service path selection for VPLS with BGP AD, and EVI for
PBB-EVPN and EVPN.
SPP for L2VPN is implemented in two steps:
• Path selection - classify incoming traffic on a per service basis.
• Path setup - set up paths with forward-class service.
Refer to Service Path Preference for MPLS VPN Sessions module for more information on SPP.

Understanding How Service Path Preference Works

SPP allows services to select a path based on policies configured in the control plane.
Consider a scenario where you have two Provider Edge (PE) routers in a setup. PE1 functions as ingress node
and PE2 functions as egress node.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
Service Path Preference for L2VPN
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