Passed Exam Today H12-821_V1.0

 VRRP and BFD Association:

VRRP (Virtual Router Redundancy Protocol) is used to provide gateway redundancy by electing a master and backup router.

Associating VRRP with BFD (Bidirectional Forwarding Detection) allows faster detection of faults on the master device or the link between the master and the backup.

Access Control Lists (ACLs) can be classified into several types, including Basic ACL (filters based on source IP), Advanced ACL (filters based on multiple parameters like source and destination IP, protocol, and ports), and Layer 2 ACL (filters based on MAC addresses). User-defined ACLs are not a standard classification ​.

In asynchronous mode, the local device sends BFD control packets at predefined intervals, and the remote device monitors the receipt of these packets to detect connectivity issues. This is one of the two operating modes in BFD, the other being demand mode ​.

In inter-AC roaming scenarios, an AC (Access Controller) can serve as the mobility server for multiple mobility groups, enabling it to manage roaming among multiple groups. However, an AC can only belong to one specific mobility group. This constraint ensures that mobility management remains streamlined and avoids conflicts. Huawei WLAN mobility configuration guides validate this setup ​.