If a user unexpectedly goes offline after obtaining an IPv6 address, the user cannot send a DHCPv6 Release message to release the requested IPv6 address, causing a waste of IPv6 resources. To avoid this, you can enable association between ND probe and DHCPv6 snooping.
After this function is enabled, the system periodically performs ND probe on the IPv6 address. If the system fails to detect the user within the specified number of probes, the system will delete the DHCPv6 snooping binding entry, construct a Release message, and send the message to notify the DHCPv6 server of releasing the IPv6 address.