H3C Technologies H3C S12500-X Series Switches - Manual (Page 141)

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Configuring a PE
Establish an ordinary IBGP peer relationship between a PE and an ASBR-PE in an AS, and an MP-EBGP
peer relationship between PEs of different ASs.
The PEs and ASBR-PEs in an AS must be able to exchange labeled IPv4 routes.
To configure a PE for inter-AS option C:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view. bgp as-number N/A
3. Configure the ASBR-PE in the
same AS as an IBGP peer. peer { group-name | ip-address }
as-number as-number
By default, no BGP peer is created.
4. Configure the PE of another
AS as an EBGP peer. peer { group-name | ip-address }
as-number as-number
By default, no BGP peer is created.
5. Enter BGP IPv4 unicast
address family view.
address-family ipv4 [ unicast ] N/A
6. Enable the PE to exchange
IPv4 unicast routes with the
peer or peer group.
peer { group-name | ip-address }
enable By default, BGP does not exchange
IPv4 unicast routes with any peer.
7. Enable the PE to exchange
labeled IPv4 routes with the
ASBR-PE in the same AS.
peer { group-name | ip-address }
label-route-capability
By default, BGP does not advertise
labeled routes to any IPv4 peer or
peer group.
8. Return to BGP view. quit N/A
9. Enter BGP-VPNv4 address
family view.
address-family vpnv4 N/A
10. Enable the PE to exchange
VPNv4 routes with the peer or
peer group.
peer { group-name | ip-address }
enable By default, BGP does not exchange
VPNv4 routes with any peer.
11. (Optional.) Configure the PE
to not change the next hop of
routes advertised to the EBGP
peer.
peer { group-name | ip-address }
next-hop-invariable
Configure this command on the RR
so the RR does not change the next
hop of advertised VPNv4 routes.
Configuring an ASBR-PE
In the inter-AS option C solution, an inter-AS LSP is required, and the public network routes advertised
between the relevant PEs and ASBRs must carry MPLS label information.
An ASBR-PE establishes common IBGP peer relationships with PEs in the same AS, and a common EBGP
peer relationship with the peer ASBR-PE. All of them can exchange labeled IPv4 routes.
Public network routes carrying MPLS labels are advertised through MP-BGP. According to RFC 3107
"Carrying Label Information in BGP-4," the label mapping information for a particular route is
piggybacked in the same BGP update message that is used to distribute the route. This capability is
implemented through BGP extended attributes and requires that BGP peers can handle labeled IPv4
routes.
To configure an ASBR-PE for inter-AS option C: