7. BGP EVPN Routes

This document defines a new BGP Network Layer Reachability Information (NLRI) called the EVPN NLRI.

The format of the EVPN NLRI is as follows:

                 +-----------------------------------+
                 |    Route Type (1 octet)           |
                 +-----------------------------------+
                 |     Length (1 octet)              |
                 +-----------------------------------+
                 | Route Type specific (variable)    |
                 +-----------------------------------+

The Route Type field defines the encoding of the rest of the EVPN NLRI (Route Type specific EVPN NLRI).

The Length field indicates the length in octets of the Route Type specific field of the EVPN NLRI.

This document defines the following Route Types:

1 - Ethernet Auto-Discovery (A-D) route + 2 - MAC/IP Advertisement route + 3 - Inclusive Multicast Ethernet Tag route + 4 - Ethernet Segment route

The detailed encoding and procedures for these route types are described in subsequent sections.

The EVPN NLRI is carried in BGP [RFC4271] using BGP Multiprotocol Extensions [RFC4760] with an Address Family Identifier (AFI) of 25 (L2VPN) and a Subsequent Address Family Identifier (SAFI) of 70 (EVPN). The NLRI field in the MP_REACH_NLRI/MP_UNREACH_NLRI attribute contains the EVPN NLRI (encoded as specified above).

In order for two BGP speakers to exchange labeled EVPN NLRI, they must use BGP Capabilities Advertisements to ensure that they both are capable of properly processing such NLRI. This is done as specified in [RFC4760], by using capability code 1 (multiprotocol BGP) with an AFI of 25 (L2VPN) and a SAFI of 70 (EVPN).

7. BGP EVPN Routes​

7. BGP EVPN Routes