EXEC privilegeclear arp-cache [interface | ip ip-address] [no-refresh]– ip ip-address (OPTIONAL): enter the keyword ip then the IP address of the ARP entry youwish to clear.– no-refresh (OPTIONAL): enter the keywords no-refresh to delete the ARP entry from CAM. Orto specify which dynamic ARP entries you want to delete, use this option with interface or ipip-address.– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/portinformation.– For a 40-Gigabit Ethernet interface, enter the keyword fortyGigE then the slot/port information.– For a port channel interface, enter the keywords port-channel then a number.– For a VLAN interface, enter the keyword vlan then a number from 1 to 4094.NOTE: Transit traffic may not be forwarded during the period when deleted ARP entries are resolvedagain and re-installed in CAM. Use this option with extreme caution.ARP Learning via Gratuitous ARPGratuitous ARP can mean an ARP request or reply.In the context of ARP learning via gratuitous ARP on Dell Networking OS, the gratuitous ARP is a request.A gratuitous ARP request is an ARP request that is not needed according to the ARP specification, but onethat hosts may send to:• detect IP address conflicts• inform switches of their presence on a port so that packets can be forwarded• update the ARP table of other nodes on the network in case of an address changeIn the request, the host uses its own IP address in the Sender Protocol Address and Target ProtocolAddress fields.In Dell Networking OS versions prior to 8.3.1.0, if a gratuitous ARP is received some time after an ARPrequest is sent, only RP2 installs the ARP information. For example:1. At time t=0 Dell Networking OS sends an ARP request for IP A.B.C.D2. At time t=1 Dell Networking OS receives an ARP request for IP A.B.C.D3. At time t=2 Dell Networking OS installs an ARP entry for A.B.C.D only on RP2.Beginning with Dell Networking OS version 8.3.1.0, when a gratuitous ARP is received, Dell NetworkingOS installs an ARP entry on all three CPUs.Enabling ARP Learning via Gratuitous ARPTo enable ARP learning via gratuitous ARP, use the following command.• Enable ARP learning via gratuitous ARP.CONFIGURATION modearp learn-enableIPv4 Routing 371
