Figure 72: Standard and Extended BGP Update Messages
Using the next-hop-self option on PE 1 causes PE 1 to set the next-hop attribute to its
own address, 172.32.12.1. Doing so is necessary because the next hop provided by CE 1 is
from VPN A’s private address space and has no meaning in the service provider core. In
addition, PE 2 must have PE 1’s address so that it can establish an LSP back to PE 1. The
next-hop address must also be carried in the MP-Reach-NLRI attribute, according to
MP-BGP.
The extended update also has the extended-communities attribute, which identifies the
VPN to which the routes are advertised. In this example, the route target is 777:1001,
identifying VPN A.
Copyright © 2010, Juniper Networks, Inc.392
JunosE 11.2.x BGP and MPLS Configuration Guide