User Manual

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the other, and establish EBGP connections through the VRF interfaces. As a result, the CE they serve will be
able to intercommunicate with and isolate from each other like locating in the same AS, with two PE routers
treating each other as their own CE. Packets will be forwarded within the AS as VPN packets in the 2-layer
label mode, and forwarded as regular IP packets between ASBR.
Figure 81-7 Multi-AS VPN Networking
 The advantage of this Multi-AS VPN mode is easy to realize: no special configuration is needed
between the two PE serving as ASBR.
 The disadvantage is poor extendibility: the PE serving as ASBR need to manage all VPN routes,
and create VPN instances for each VPN. This will cause too many VPN-IPv4 routes on PE.
81.2 BGP MPLS VPN Configuration
BGP MPLS VPN configuration task sequence:
1. Enable globally MPLS (necessary)
2. Configure VPN instances (necessary)
(1) Create VPN instances, and enter the VPN instance view.
(2) RD Configure the VPN instance RD
(3) Configure the VPN instance RT
(4) Configure the VPN instance to relate with the interface
3. Configure basic MPLS VPN (necessary)
(1) Configure to use EBGP between PE-CE
1) Configure the remote PE as the public network VPNv4 neighbor
2) Enter the BGP-VPN instance view
3) Configure CE as the VPN private network neighbor
4) Advertise local private network routes
BGP/MPLS backbone
AS 100
CE-1
VPN-1
PE-2
ASBR-1
(PE)
PE-1
CE-3
VPN-1
PE-4
ASBR-2
(PE)
PE-3
CE-4
VPN
Instance
BGP/MPLS backbone
AS 200
MP-IBGP
MP-IBGP
MP-IBGP
MP-IBGP
EBGP
LSP1
VPN LSP1
LSP2
VPN LSP2
IP forwarding
VPN-2
VPN-2
CE-2