300-515 SPVI: Implementing Cisco Service Provider VPN Services

A VRF imports an exported VPN route only when the route’s route target matches one of its import route targets. The Internet VRF exports the default route with route target 300:3, which CE2 imports but CE1 does not; therefore, only CE2 can use that default route. VPNv4 reachability is exchanged between PE routers through MP-BGP.

Carrier Supporting Carrier requires the CSC-CE and CSC-PE to exchange IPv4 routes together with MPLS labels through BGP. The PE neighbor already uses the IPv4 labeled-unicast address family, so the CE neighbor must also be configured for address-family ipv4 labeled-unicast to enable labeled route exchange.

EVPN single-active and all-active are multihoming mechanisms for CE devices. Single-active forwards through one active provider-edge attachment for an Ethernet segment, whereas all-active can forward through multiple attached provider-edge devices.

An EVPN E-Tree service allows a root to send traffic to another root or to a leaf, while leaf-to-leaf traffic is restricted. Known unicast traffic from a root to another root is therefore permitted.

An IOS XR L2 transport subinterface matching VLAN 10 uses rewrite ingress tag pop 1 symmetric to remove one incoming 802.1Q VLAN tag. The symmetric keyword applies the complementary tag handling in the reverse direction, and the subinterface can be used as the attachment circuit for the EoMPLS xconnect.