peer listen-as-segment (BGP-VPN instance view)

Function

The peer listen-as-segment command specifies a peer AS range from which a dynamic EBGP peer group listens for BGP connection requests.

The undo peer listen-as-segment command deletes the specified peer AS range from which a dynamic EBGP peer group listens for BGP connection requests.

By default, no peer AS range from which a dynamic EBGP peer group listens for BGP connection requests is specified.

Format

peer group-name listen-as-segment begin-as begin-asn end-as end-asn

undo peer group-name listen-as-segment begin-as begin-asn end-as end-asn

Parameters

Parameter	Description	Value
group-name	Specifies the name of a peer group.	The value is a string of 1 to 47 case-sensitive characters, spaces not supported.
begin-as begin-asn	Specifies the start AS number in an AS range.	For an integral AS number, the value is an integer ranging from 1 to 4294967295. For an AS number in dotted notation, the value is in the format of x.y, where x and y are integers ranging from 1 to 65535 and from 0 to 65535, respectively.
end-as end-asn	Specifies the end AS number in an AS range.	For an integral AS number, the value is an integer ranging from 1 to 4294967295. For an AS number in dotted notation, the value is in the format of x.y, where x and y are integers ranging from 1 to 65535 and from 0 to 65535, respectively.

Parameter

Description

Value

group-name

Specifies the name of a peer group.

The value is a string of 1 to 47 case-sensitive characters, spaces not supported.

begin-as begin-asn

Specifies the start AS number in an AS range.

For an integral AS number, the value is an integer ranging from 1 to 4294967295.

For an AS number in dotted notation, the value is in the format of x.y, where x and y are integers ranging from 1 to 65535 and from 0 to 65535, respectively.

end-as end-asn

Specifies the end AS number in an AS range.

For an integral AS number, the value is an integer ranging from 1 to 4294967295.

For an AS number in dotted notation, the value is in the format of x.y, where x and y are integers ranging from 1 to 65535 and from 0 to 65535, respectively.

Views

BGP-VPN instance view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

To specify a peer AS range from which a dynamic EBGP peer group listens for BGP connection requests, run the peer listen-as-segment command. The dynamic BGP peer function enables BGP to listen for BGP connection requests from a specified network segment, dynamically establish BGP peer relationships, and add these peers to the same dynamic peer group. This spares you from adding or deleting BGP peer configurations in response to each change in BGP peers.

Precautions

If the undo peer listen-as-segment command is run, all connections established between the local device and the dynamic peers in the specified AS-Segment are also deleted. Therefore, exercise caution when running this command.

When you run the undo peer listen-as-segment command, ensure that the start and end AS numbers in the AS range to be deleted are the same as those in the configured AS range.

Example

# Configure the dynamic EBGP peer group named ex to listen for BGP connection requests from the peer AS range 200 to 300.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpn1
[*HUAWEI-vpn-instance-vpn1] ipv4-family
[*HUAWEI-vpn-instance-vpn1-af-ipv4] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpn1-af-ipv4] quit
[*HUAWEI-vpn-instance-vpn1] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] vpn-instance vpn1
[*HUAWEI-bgp-instance-vpn1] group ex listen external
[*HUAWEI-bgp-instance-vpn1] peer ex listen-as-segment begin-as 200 end-as 300