MP-BGP extension for EVPN

The following are some important EVPN route types:

Ethernet auto-discovery route—Advertises Ethernet Segment (ES) information in multihomed sites.
MAC/IP advertisement route—Advertises MAC reachability information and host route information (host ARP or ND information).
Inclusive Multicast Ethernet tag (IMET) route—Advertises VTEP and VxLAN mappings for automating VTEP discovery, VxLAN tunnel establishment, and VxLAN tunnel assignment.
Ethernet Segment route—Advertises ES and VTEP mappings.
IP Prefix advertisement route—Advertises BGP IPv4 or IPv6 unicast routes as IP prefixes.

MP-BGP uses the route distinguisher (RD) field to differentiate BGP EVPN routes of different L2 domains and uses route targets to control the advertisement and acceptance of BGP EVPN routes. MP-BGP supports the following types of route targets:

Export Route Target—A VTEP sets the export targets for BGP EVPN routes learned from the local site before advertising them to remote VTEPs.
Import Route Target—A VTEP checks the export targets of BGP EVPN routes received from remote VTEPs. The VTEP imports the BGP EVPN routes only when their export targets match the local import targets.