peer connect-interface
Function
The peer connect-interface command specifies a source interface from which BGP packets are sent, and a source address used for initiating a connection.
The undo peer connect-interface command restores the default setting.
By default, the outbound interface of a BGP packet serves as the source interface of the BGP packet.
Format
peer { group-name | ipv4-address } connect-interface interface-type interface-number [ ipv4-source-address ]
peer { group-name | ipv6-address } connect-interface interface-type interface-number [ ipv6-source-address ]
undo peer { group-name | ipv4-address | ipv6-address } connect-interface
Parameters
| Parameter | Description | Value |
|---|---|---|
| group-name | Specifies the name of a peer group. | The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string. |
| ipv4-address | Specifies the IPv4 address of a peer. | It is in dotted decimal notation. |
| interface-type interface-number | Specifies the type and number of an interface. | - |
| ipv6-address | Specifies the IPv6 address of a peer. | The value is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X. |
| ipv4-source-address | Specifies an IPv4 source address used for establishing a connection. | It is in dotted decimal notation. |
| ipv6-source-address | Specifies an IPv6 source address used for establishing a connection. | The value is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X. |
ipv4-address is valid only in the BGP view and BGP-VPN instance IPv4 address family view.
ipv6-address is valid only in the BGP view and BGP-VPN instance IPv6 address family view.
Views
BGP view, BGP-VPN instance IPv4 address family view, BGP-VPN instance IPv6 address family view
Usage Guidelines
Usage Scenario
To establish a BGP peer connection between two indirectly connected physical interfaces, the peer connect-interface command must be run on both sides.
To establish a BGP peer connection between a local loopback interface and a remote interface, the loopback interface must be specified as the source interface in the command. To establish a BGP peer connection between a local physical interface and a remote interface, the physical interface must be specified as the source interface in the command.
- If multiple IP addresses are configured for the physical interface that needs a BGP peer connection established with a remote interface, the peer connect-interface command must be run, with ipv4-source-address or ipv6-source-address set to the source IP address.
- If two devices need multiple BGP peer connections established through different interfaces, the peer connect-interface command must be run for each BGP peer connection, with the source interface specified.
Prerequisites
Peer relationships have been established using the peer as-number command.
Precautions
Running the peer connect-interface command causes the teardown and re-establishment of peer relationships.
Because the BGP peer relationships in various address families on the same device share one TCP connection, connect-interface configured in the BGP view can be inherited in the IPv4 unicast address family.
To enable a device to send BGP packets even if its physical interface fails, you can configure the device to use a loopback interface as the source interface of the BGP packets. When configuring a device to use a loopback interface as the source interface of BGP packets, note the following points:
The loopback interface of the device's BGP peer must be reachable.
In the case of an EBGP connection, the peer ebgp-max-hop command needs to be run to enable the two devices to establish an indirect peer relationship.
If the specified interface borrows the IP address of another interface and then the IP address of the specified interface is changed, BGP still uses the borrowed IP address to keep the connection if no connection reestablishment is triggered, and data receiving and sending is not affected; if connection reestablishment is triggered, BGP uses the new IP address to reestablish the connection.