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.
| Parameter | Description | Value |
|---|---|---|
| peerIpv6Addr |
Specifies the IPv6 address of a BGP EVPN peer. |
The value is a 32-digit hexadecimal number, in the format of X:X:X:X:X:X:X:X. |
| num |
Specifies the maximum number of times that the local AS number can be repeated. |
The value is an integer that ranges from 1 to 10. The default value is 1. |
Usage Scenario
Generally, BGP uses AS numbers to detect routing loops. The local AS number configured using the bgp command and the fake AS number configured using the peer fake-as command are compared with the AS_Path carried in the received route. The number of loops is the largest. In Hub and Spoke networking, if EBGP runs between the PE and CE of the Hub, the routing information advertised by the Hub-PE to the Hub-CE carries the AS number of the Hub-CE. When the Hub-PE receives the routing update from the Hub-CE, the routing update carries the AS number of the Hub-PE. In this case, the Hub-PE cannot receive the routing update.
To ensure correct route transmission in the Hub and Spoke networking, configure the BGP peers on the path from the Hub-CE to the Spoke-CE to allow the routes with the same AS number in the AS_Path attribute to pass.Prerequisites
BGP peers have been enabled in the BGP-EVPN address family view.
Configuration Impact
If the peer command is run more than once for the same peer, the latest configuration overrides the previous one.
<HUAWEI> system-view [~HUAWEI] bgp 200 [*HUAWEI-bgp] peer 2001:db8:1::1 as-number 200 [*HUAWEI-bgp] l2vpn-family evpn [*HUAWEI-bgp-af-evpn] peer 2001:db8:1::1 enable [*HUAWEI-bgp-af-evpn] peer 2001:db8:1::1 allow-as-loop 2