Specifying the source interface for TCP connections
BGP uses TCP as the transport layer protocol. By default, BGP uses the output interface of the optimal router to a peer as the source interface for establishing TCP connections to the peer. If a BGP router has multiple links to a peer, when the source interface fails, BGP has to reestablish TCP connections, causing network oscillation. Therefore, it is recommended to use a loopback interface as the source interface to enhance stability of BGP connections.
Follow these steps to specify the source interface of TCP connections:
To do... |
Use the command... |
Remarks |
|---|---|---|
Enter global configuration context |
configuration |
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Enter BGP context |
bgp
as-number
|
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Specify the source interface for establishing TCP connections to a neighbor. |
neighbor {ip-address}
update-source {ip-address}
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Required. By default, BGP uses the outbound interface of the best route to the BGP peer as the source interface for establishing a TCP connection to the peer. |