3Com 3C13636 Configuration Manual page 878

3Com Router 3000 Ethernet Family
Configuration Guide
PEs in different ASs establish Multihop EBGP connections with each other and
exchange VPN-IPv4 routes.
CE-1 CE-1
VPN-1 VPN-1
CE-2 CE-2
VPN-2 VPN-2
Figure 3-11 Network diagram for advertising labeled VPN-IPv4 routes through
Multihop MP-EBGP between PEs
To improve the extensibility, you can specify an RR in each AS to keep all VPN-IPv4
routes and exchange VPN-IPv4 routes with PEs in the AS. The RRs in two ASs
establish multi-AS VPNv4 connection with each other and advertise VPN-IPv4 routes,
as shown in the following figure.
CE-1 CE-1
VPN-1 VPN-1
CE-2 CE-2
VPN-2 VPN-2
Figure 3-12 Network diagram for multi-AS VPN Option C adopting RR
BGP/MPLS backbone BGP/MPLS backbone
AS 100 AS 100
PE-1 PE-1
ASBR-1 ASBR-1
(PE) (PE)
MP-IBGP MP-IBGP
PE-2 PE-2 MP-IBGP MP-IBGP
BGP/MPLS backbone BGP/MPLS backbone
PE-1 PE-1
AS 100 AS 100
ASBR-1 ASBR-1
RR-1 RR-1
(PE) (PE)
MP-IBGP MP-IBGP
MP-IBGP MP-IBGP
PE-2 PE-2
3Com Corporation
Chapter 3 BGP/MPLS VPN Configuration
BGP/MPLS backbone BGP/MPLS backbone
Multi-hop MP-EBGP Multi-hop MP-EBGP
ASBR-2 ASBR-2
(PE) (PE)
MP-EBGP MP-EBGP
Multi-hop MP-EBGP Multi-hop MP-EBGP
VPN LSP VPN LSP
LSP LSP
BGP/MPLS backbone BGP/MPLS backbone
AS 200 AS 200
ASBR-2 ASBR-2
(PE) (PE)
MP-EBGP MP-EBGP
MP-IBGP MP-IBGP
Multi-hop MP-EBGP Multi-hop MP-EBGP
VPN LSP VPN LSP
LSP LSP
3-16
CE-3 CE-3
VPN-1 VPN-1
AS 200 AS 200
PE-3 PE-3
MP-IBGP MP-IBGP
MP-IBGP MP-IBGP
PE-4 PE-4
CE-4 CE-4
VPN-2 VPN-2
CE-3 CE-3
VPN-1 VPN-1
PE-3 PE-3
RR-2 RR-2
MP-IBGP MP-IBGP
PE-4 PE-4
CE-4 CE-4
VPN-2 VPN-2