peer as-path-filter export (BGP multi-instance VPN instance IPv4 address family view)

Function

The peer as-path-filter export command configures a policy based on an AS_Path list for filtering BGP routes to be advertised to a specified peer.

The undo peer as-path-filter export command cancels this configuration.

By default, no policy based on an AS_Path list is configured for filtering BGP routes to be advertised to a peer, and all the BGP routes will be advertised to the peer.

Format

peer ipv4-address as-path-filter { number | name } export

undo peer ipv4-address as-path-filter { number | name } export

Parameters

Parameter	Description	Value
ipv4-address	Specifies the IPv4 address of a peer.	It is in dotted decimal notation.
number	Specifies the number of an AS_Path filter.	The value is an integer ranging from 1 to 256.
name	Specifies the name of an AS_Path filter.	The value is a string of 1 to 51 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.

Parameter

Description

Value

ipv4-address

Specifies the IPv4 address of a peer.

It is in dotted decimal notation.

number

Specifies the number of an AS_Path filter.

The value is an integer ranging from 1 to 256.

name

Specifies the name of an AS_Path filter.

The value is a string of 1 to 51 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.

Views

BGP multi-instance VPN instance IPv4 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

After the peer as-path-filter export command is used to apply a route filtering policy based on an AS_Path list to BGP routes to be advertised to a specified peer, the routers that do not match the policy are filtered out.

Prerequisites

The ip as-path-filter command has been run to define an AS-Path filter.

Precautions

Only one AS_Path filter can be used to filter routes to be advertised to the same peer.

The peer as-path-filter export command is mutually exclusive with the peer route-filter export commands.

Example

# Configure an AS_Path filter for a peer.

<HUAWEI> system-view
[~HUAWEI] ip as-path-filter 3 permit ^10_
[~HUAWEI] ip vpn-instance vpna
[*HUAWEI-vpn-instance-vpna] ipv4-family
[*HUAWEI-vpn-instance-vpna-af-ipv4] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpna-af-ipv4] vpn-target 111:1 both
[*HUAWEI-vpn-instance-vpna-af-ipv4] quit
[*HUAWEI-instance-vpna] quit
[*HUAWEI] bgp 100 instance a
[*HUAWEI-bgp-instance-a] ipv4-family vpn-instance vpna
[*HUAWEI-bgp-instance-a-vpna] peer 10.1.1.1 as-number 100
[*HUAWEI-bgp-instance-a-vpna] peer 10.1.1.1 as-path-filter 3 export