7.6. ES-Import Route Target

This is a new transitive Route Target extended community carried with the Ethernet Segment route. When used, it enables all the PEs connected to the same multihomed site to import the Ethernet Segment routes. The value is derived automatically for the ESI Types 1, 2, and 3, by encoding the high-order 6-octet portion of the 9-octet ESI Value, which corresponds to a MAC address, in the ES-Import Route Target. The format of this Extended Community is as follows:

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    | Type=0x06     | Sub-Type=0x02 |          ES-Import            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ES-Import Cont'd                          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

This document expands the definition of the Route Target extended community to allow the value of the high-order octet (Type field) to be 0x06 (in addition to the values specified in [RFC4360]). The low-order octet (Sub-Type field) value 0x02 indicates that this Extended Community is of type "Route Target". The new Type field value 0x06 indicates that the structure of this RT is a 6-octet value (e.g., a MAC address). A BGP speaker that implements RT Constraint [RFC4684] MUST apply the RT Constraint procedures to the ES-Import RT as well.

For procedures and usage of this attribute, please see Section 8.1 ("Multihomed Ethernet Segment Auto-discovery").

7.6. ES-Import Route Target​

7.6. ES-Import Route Target