3Com S7906E Configuration Manual page 1617

Figure 1-27 Configure BGP AS number substitution
Loop0
Vlan-int11
CE 1
Vlan-int11
Vlan-int12
Device Interface
CE 1 Vlan-int11
Vlan-int12
PE 1 Loop0
Vlan-int11
Vlan-int12
CE 2 Vlan-int12
Vlan-int11
Configuration procedure
1) Configuring basic MPLS L3VPN
Configure OSPF on the MPLS backbone to allow the PEs and P device to learn the routes of the
loopback interfaces from each other.
Configure MPLS basic capability and MPLS LDP on the MPLS backbone to establish LDP LSPs.
Establish MP-IBGP peer relationship between the PEs to advertise VPN IPv4 routes.
Configure the VPN instance of VPN 1 on PE 2 to allow CE 2 to access the network.
Configure the VPN instance of VPN 1 on PE 1 to allow CE 1 to access the network.
Configure BGP between PE 1 and CE 1, and between PE 2 and CE 2 to inject routes of CEs into
PEs.
After completing the above configurations, if you issue the display ip routing-table command on CE 2,
you should see that CE 2 has learned the route to network segment 10.1.1.0/24, where the interface
used by CE 1 to access PE 1 resides; but has not learned the route to the VPN (100.1.1.0/24) behind
CE 1. You should see the similar situation on CE 1.
<CE2> display ip routing-table
Routing Tables: Public
Destinations : 8
Destination/Mask
10.1.1.0/24
10.1.1.1/32
10.2.1.0/24
10.2.1.1/32
10.2.1.2/32
MPLS backbone
Loop0
Vlan-int12
Vlan-int12
PE 1
P
VPN 1
IP address
10.1.1.1/24
100.1.1.1/24
1.1.1.9/32
10.1.1.2/24
20.1.1.1/24
10.2.1.1/24
200.1.1.1/24
Routes : 8
Proto Pre Cost
BGP 255 0
BGP 255 0
Direct 0 0
Direct 0 0
Direct 0 0
1-102
Vlan-int11
Loop0
Vlan-int11
Vlan-int12
PE 2
Vlan-int12
VPN 1
Device Interface
P Loop0
Vlan-int11
Vlan-int12
PE 2 Loop0
Vlan-int11
Vlan-int12
NextHop Interface
10.2.1.2 Vlan12
10.2.1.2 Vlan12
10.2.1.1 Vlan12
127.0.0.1 InLoop0
10.2.1.2 Vlan12
CE 2
Vlan-int11
IP address
2.2.2.9/32
30.1.1.1/24
20.1.1.2/24
3.3.3.9/32
30.1.1.2/24
10.2.1.2/24