H3C Technologies H3C S7500E Series Switches - Manual (Page 272)

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Configuration Procedure
When CEs at different sites have the same AS number, you need to configure the BGP AS number
substitution function to avoid route loss.
With the BGP AS number substitution function, when a PE advertises a route to a CE of the specified
peer, if an AS number identical to that of the CE exist in the AS_PATH of the route, it will be replaced
with that of the PE before the route is advertised.
Follow these steps to configure the BGP AS number substitution function:
To do… Use the command… Remarks
Enter system view system-view —
Enter BGP view bgp as-number Required
Enter BGP VPN instance view
ipv4-family vpn-instance
vpn-instance-name
Required
Enable the BGP AS number
substitution function
peer { ip-address | group-name }
substitute-as
Required
Disabled by default
For information about the peer { ip-address | group-name } substitute-as command, see BGP
Commands in the Layer 3 - IP Routing Command Reference.
Displaying and Maintaining MPLS L3VPN
Resetting BGP Connections
When BGP configuration changes, you can use the soft reset function or reset BGP connections to
make new configurations take effect. Soft reset requires that BGP peers have route refreshment
capability (supporting Route-Refresh messages).
To do… Use the command… Remarks
Perform a soft reset of the BGP
connections in a specified VPN
instance
refresh bgp vpn-instance
vpn-instance-name { ip-address |
all | external | group
group-name } { export | import }
Available in user view
Perform a soft reset of the BGP
VPNv4 connections
refresh bgp vpnv4 { ip-address |
all | external | group group-name
| internal } { export | import }
Available in user view