H3C Technologies H3C S10500 Series Switches - Manual (Page 266)

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To do… Use the command… Remarks
Specify not to change the next hop
of a route when advertising it to an
eBGP peer
peer { group-name | ip-address }
next-hop-invariable
Optional
By default, a device uses its
address as the next hop when
advertising a route to its eBGP
peer.
Specify the preference value for the
routes received from the peer/peer
group
peer { group-name | ip-address }
preferred-value value Optional
0 by default
Make BGP updates to be sent carry
no private AS numbers peer { group-name | ip-address }
public-as-only
Optional
By default, a BGP update carries
private AS numbers.
Apply a routing policy to a peer or
peer group
peer { group-name | ip-address }
route-policy route-policy-name
{ export | import }
Optional
By default, no routing policy is
applied to a peer or peer group.
NOTE:
For information about BGP routing, see Layer 3—IP Routing Configuration Guide.
Configuring inter-AS VPN
If the MPLS backbone on which the VPN routes rely spans multiple ASs, you need to configure inter-AS
VPN.
Three inter-AS VPN solutions are available. You can choose them as required.
Configuration prerequisites
Before you configure inter-AS VPN, complete the following tasks:
• Configure an IGP for the MPLS backbones in each AS to implement IP connectivity of the backbones
in the AS
• Configure basic MPLS for the MPLS backbones of each AS
• Configure MPLS LDP for the MPLS backbones so that LDP LSPs can be established
• Configure basic MPLS L3VPN for each AS
NOTE:
When configuring basic MPLS L3VPN for each AS, specific configurations may be required on PEs or
ASBR PEs. This depends on the inter-AS VPN solution selected.
Configuring inter-AS option A
Inter-AS option A applies to scenarios where the number of VPNs and that of VPN routes on the PEs are
relatively small. It is simple to implement.
To configure inter-AS option A, complete the following tasks:
• Configure basic MPLS L3VPN on each AS.