According to the Huawei documents and resources, the VRRP preemption delay is the time that an AC waits before preempting another AC with a lower priority. If the VRRP preemption delay is set to a small value, the following problems may occur after a master/backup switchover:
* B. A master/backup switchback is triggered too quickly. If the master AC recovers soon after a switchover, it may preempt the backup AC again and become the master AC. This may cause frequent switchovers and affect network stability 1 .
* C. Backup information is incomplete. If the backup AC takes over services from the master AC too quickly, it may not have received all the data sy nchronized from the master AC through HSB. This may cause service interruption or data loss 2 .
Therefore, B and C are the correct answers. References: 1 : https://support.huawei.com/enterprise/en /doc
/EDOC1100064368/80fc2ebd/example-for-configuring-vrrp-hsb 2 : https://support.huawei.com/enterprise/en
/doc/EDOC1100096325/1a753937/vrr p-hsb-configuration

The display sync-configuration compare command is used to check whether the public configurations on two WACs are consistent after wireless configuration synchronization. The command output shows the differences between the configurations on the master and backup WACs. In this case, the configuration of vap- profile name 3 exists on the master WAC but not on the backup WAC.
References: https://support.huawei.com/enterprise/en/doc/EDOC1100058940/8a8f1c9b/display-sync- configuration-compare