Internet 10.1.2.4 17 08:00:20:b7:bd:32 Ma 1/1 - CPDell#Enabling Proxy ARPBy default, Proxy ARP is enabled. To disable Proxy ARP, use the no proxy-arp command in the interface mode.To re-enable Proxy ARP, use the following command.• Re-enable Proxy ARP.INTERFACE modeip proxy-arpTo view if Proxy ARP is enabled on the interface, use the show config command in INTERFACE mode. If it is not listed in theshow config command output, it is enabled. Only non-default information is displayed in the show config command output.Clearing ARP CacheTo clear the ARP cache of dynamically learnt ARP information, use the following command.• Clear the ARP caches for all interfaces or for a specific interface by entering the following information.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 you wish to clear.– no-refresh (OPTIONAL): enter the keywords no-refresh to delete the ARP entry from CAM. Or to specify whichdynamic ARP entries you want to delete, use this option with interface or ip ip-address.– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port information.– 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 resolved again 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 requestis an ARP request that is not needed according to the ARP specification, but one that 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 Protocol Address fields.In Dell Networking OS versions prior to 8.3.1.0, if a gratuitous ARP is received some time after an ARP request is sent, only RP2installs 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.DIPv4 Routing 325
