The method includes the steps of: a) creating a high availability (HA) network equipment cluster and network connection and assigning a virtual destination IP address (VIP address); b) defining an operating device and a backup device in the HA network equipment cluster, wherein the operating device and the backup device have respective physical addresses (MAC addresses); c) disposing a packet detection controller in the backup device; d) informing the operating device when the packet detection controller detects a packet with the VIP address as a destination; and e) the operating device announcing an ARP (Address Resolution Protocol) broadcast packet with correspondence of the VIP address and its own MAC address to drive an external network device with wrong ARP correspondence to make ARP update.