peer allow-as-loop (BGP-VPN instance IPv6 address family view) (IPv6)

Function

The peer allow-as-loop command sets the number of local AS number repetitions.

The undo peer allow-as-loop command cancels the configuration.

By default, the local AS number cannot be repeated.

Format

peer ipv6-address allow-as-loop [ number ]

undo peer ipv6-address allow-as-loop

Parameters

Parameter	Description	Value
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.
number	Specifies the number of local AS number repetitions.	The value is an integer ranging from 1 to 10. The default value is 1.

Parameter

Description

Value

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.

number

Specifies the number of local AS number repetitions.

The value is an integer ranging from 1 to 10. The default value is 1.

Views

BGP-VPN instance IPv6 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

Generally, BGP uses AS numbers to detect routing loops. The AS numbers in the AS_Path of each received route are matched against the local AS number configured using the bgp command and the fake AS number configured using the peer fake-as command. The largest number of times any of the configured AS numbers is repeated is considered as the routing loop count.

After the peer allow-as-loop command is run to set the number of times the local AS number is repeated, the BGP speaker allows the routes with repeated AS numbers in the AS_Path attribute to pass, meeting the requirements of special scenarios.

Prerequisites

Peer relationships have been established using the peer as-number command.

Configuration Impact

If the peer allow-as-loop command is run for a peer multiple times, the latest configuration overrides the previous one.

Example

# Set the number of local AS number repetitions to 2.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpna
[*HUAWEI-vpn-instance-vpna] ipv6-family
[*HUAWEI-vpn-instance-vpn1-af-ipv6] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpna-af-ipv6] quit
[*HUAWEI-vpn-instance-vpna] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] ipv6-family vpn-instance vpna
[*HUAWEI-bgp-6-vpna] peer 2001:DB8:1::1 as-number 100
[*HUAWEI-bgp-6-vpna] peer 2001:DB8:1::1 allow-as-loop 2