EVPN MPLS Seamless Integration with VPLS
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address-family l2vpn evpn
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EVPN MPLS Seamless Integration with VPLS
VPLS is a widely-deployed L2VPN technology. As service providers are looking to adopt EVPN on their
existing VPLS networks, it is required to provide a mechanism by which EVPN can be introduced without a
software upgrade. The EVPN MPLS Seamless Integration with VPLS feature allows EVPN service introduced
gradually in the network on a few PE nodes at a time. It eliminates the need to network wide software upgrade
at the same time. This feature allows a VPLS service migrated to EVPN service. This feature allows for staged
migration where new EVPN sites can be provisioned on existing VPLS enabled PEs. This feature also allows
for the co-existence of PE nodes running EVPN and VPLS for the same VPN instance. This allows VPLS or
legacy network to be upgraded to the next generation EVPN network without service disruption.
Migrate VPLS Network to EVPN Network through Seamless Integration
In EVPN network, VPN instances are identified by EVPN instance ID (EVI-ID). Similar to other L2VPN
technologies, EVPN instances are also associated with route-targets and route-distinguisher. EVPN uses
control plane for learning and propagating MAC unlike traditional VPLS, where MAC is learnt in the data
plane (learns using "flood and learn technique"). In EVPN, MAC routes are carried by MP-BGP protocol. In
EVPN enabled PEs, PEs import the MAC route along with the label to their respective EVPN forwarding
table only if their route targets (RTs) match. An EVPN PE router is capable of performing VPLS and EVPN
L2 bridging in the same VPN instance. When both EVPN and BGP-AD PW are configured in a VPN instance,
the EVPN PEs advertise the BGP VPLS auto-discovery (AD) route as well as the BGP EVPN Inclusive
Multicast route (type-3) for a given VPN Instance. Route type-3 referred to as ingress replication multicast
route, is used to send broadcast, unknown unicast, and multicast (BUM) traffic. Other remote PEs import
type-3 routes for the same VPN instance only if the sending PE RTs match with their configured RT. Thus,
at the end of these route-exchanges, EVPN capable PEs discover all other PEs in the VPN instance and their
associated capabilities. The type-3 routes used by PE to send its BUM traffic to other PEs ensure that PEs
with the same RTs receive the BUM traffic. EVPN advertises the customer MAC address using type-2 route.
This feature allows you to upgrade the VPLS PE routers to EVPN one by one and the network works without
any service disruption. Consider the following topology where PE1, PE2, PE3, and PE4 are interconnected
in a full-meshed network using VPLS PW.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
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multipath
route-policy passall in
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advertise l2vpn evpn re-originated stitching-rt
EVPN Features