Netgear XSM4324FS CLI Manual Software Version 12.x - Page 651

M4300 Intelligent Edge Series Fully Managed Stackable Switches from the hardware. Traffic to the host continues to be forwarded in hardware without interruption. If the entry is not being used to forward data packets, then the entry is deleted from the ARP cache, unless the dynamic renew option is enabled. If the dynamic renew option is enabled, the system sends an ARP request to renew the entry. When an entry is not renewed, it is removed from the hardware and subsequent data packets to the host trigger an ARP request. Traffic to the host may be lost until the router receives an ARP reply from the host. Gateway entries, entries for a neighbor router, are always renewed. The dynamic renew option applies only to host entries. The disadvantage of enabling dynamic renew is that once an ARP cache entry is created, that cache entry continues to take space in the ARP cache as long as the neighbor continues to respond to ARP requests, even if no traffic is being forwarded to the neighbor. In a network where the number of potential neighbors is greater than the ARP cache capacity, enabling dynamic renew could prevent some neighbors from communicating because the ARP cache is full. Default Format Mode disabled arp dynamicrenew Privileged EXEC no arp dynamicrenew This command prevents dynamic ARP entries from renewing when they age out. Format Mode no arp dynamicrenew Privileged EXEC arp purge This command causes the specified IP address to be removed from the ARP cache. Only entries of type dynamic or gateway are affected by this command. The ipaddr parameter is the IP address that must be removed from the ARP cache. The optional interface keyword and its associated parameters specify the interface from which the IP address must be removed. Format Mode arp purge ipaddr [interface {unit/slot/port | vlan-id}] Privileged EXEC Routing Commands 651 CLI Command Reference Manual