When the switch is configured with the MFF function and a static gateway address, users with static IP addresses must send ARP request packets or gratuitous ARP packets to trigger creation of MFF user entries on the switch. Otherwise, the users cannot ping each other. When you use a tester to simulate users with static IP addresses, ensure that the tester can send ARP request packets and gratuitous ARP packets. If the tester cannot send ARP request packets or gratuitous ARP packets, the switch does not create MFF entries for the users with static IP addresses, and the users cannot ping each other.