A large-scale BGP network has a large number of peers.

In Huawei’s implementation of BGP peer groups, the goal is to ease configuration in large-scale BGP deployments. When you define a peer group, all peers within that group inherit common settings.

For IBGP peer groups, since the peers are in the same AS, you do not need to specify an AS number.

For EBGP peer groups, since the peers are in different ASes, you must specify the AS number during peer group configuration.

✅ Official Reference from Huawei:

" When configuring an IBGP peer group, the AS number does not need to be specified because all members belong to the same AS. However, when configuring an EBGP peer group, the peer AS must be explicitly specified. "

— [Huawei HCIA-Datacom Certification Guide – BGP Chapter]