H3C Technologies H3C S10500 Series Switches - Manual (Page 301)

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Configuring inter-AS option A
Network requirements
• CE 1 and CE 2 belong to the same VPN. CE 1 accesses the network through PE 1 in AS 100 and
CE 2 accesses the network through PE 2 in AS 200.
• Inter-AS MPLS L3VPN is implemented using option A, where the VRF-to-VRF method is used to
manage VPN routes.
• The MPLS backbone in each AS runs OSPF.
Figure 74 Configure inter-AS option A
Loop0 Loop0
Loop0 Loop0
Vlan-int12
CE 1 CE 2
AS 65001 AS 65002
PE 1 PE 2
ASBR-PE 2 ASBR-PE 1
MPLS backbone MPLS backbone
AS 100 AS 200
Vlan-int12 Vlan-int12
Vlan-int12
Vlan-int11
Vlan-int11
Vlan-int12 Vlan-int12
Vlan-int11
Vlan-int11
Device Interface IP address Device Interface IP address
CE 1 Vlan-int12 10.1.1.1/24 CE 2 Vlan-int12 10.2.1.1/24
PE 1 Loop0 1.1.1.9/32 PE 2 Loop0 4.4.4.9/32
Vlan-int12 10.1.1.2/24 Vlan-int12 10.2.1.2/24
Vlan-int11 172.1.1.2/24 Vlan-int11 162.1.1.2/24
ASBR-PE 1 Loop0 2.2.2.9/32 ASBR-PE 2 Loop0 3.3.3.9/32
Vlan-int11 172.1.1.1/24 Vlan-int11 162.1.1.1/24
Vlan-int12 192.1.1.1/24 Vlan-int12 192.1.1.2/24
Configuration procedure
1. Configure an IGP on the MPLS backbone to ensure IP connectivity in the backbone
This example uses OSPF. (Details not shown)
NOTE:
The 32-bit loopback interface address used as the LSR ID needs to be advertised by OSPF.
After you complete the configurations, each ASBR PE and the PE in the same AS can establish OSPF
adjacencies. Issue the display ospf peer command. The output shows that the adjacencies reach the Full
state, and that PEs can learn the routes to the loopback interfaces of each other.