Information About EVPN-VPWS Single Homed
The EVPN-VPWS single homed solution requires per EVI Ethernet Auto Discovery route. EVPN defines a new BGP Network Layer Reachability Information (NLRI) used to carry all EVPN routes. BGP Capabilities Advertisement used to ensure that two speakers support EVPN NLRI (AFI 25, SAFI 70) as per RFC 4760.
The architecture for EVPN VPWS is that the PEs run Multi-Protocol BGP in control-plane. The following image describes the EVPN-VPWS configuration:
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The VPWS service on PE1 requires the following three elements to be specified at configuration time: -
The VPN ID (EVI)
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The local AC identifier (AC1) that identifies the local end of the emulated service.
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The remote AC identifier (AC2) that identifies the remote end of the emulated service.
PE1 allocates a MPLS label per local AC for reachability.
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The VPWS service on PE2 is set in the same manner as PE1. The three same elements are required and the service configuration must be symmetric.
PE2 allocates a MPLS label per local AC for reachability.
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PE1 advertise a single EVPN per EVI Ethernet AD route for each local endpoint (AC) to remote PEs with the associated MPLS label.
PE2 performs the same task.
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On reception of EVPN per EVI EAD route from PE2, PE1 adds the entry to its local L2 RIB. PE1 knows the path list to reach AC2, for example, next hop is PE2 IP address and MPLS label for AC2.
PE2 performs the same task.