Concept Guide
To view if Proxy ARP is enabled on the interface, use the show config command in INTERFACE mode. If it is not listed in the show
config command output, it is enabled. Only non-default information is displayed in the show config command output.
Clearing ARP Cache
To clear the ARP cache of dynamically learnt ARP information, use the following command.
• Clear the ARP caches for all interfaces or for a specic interface by entering the following information.
EXEC privilege
clear 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 which dynamic
ARP entries you want to delete, use this option with interface or ip ip-address.
– For a 1-GigabitEthernet interface, enter the keyword GigabitEthernet then the slot/port information.
– For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet 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 trac 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 ARP
Gratuitous ARP can mean an ARP request or reply.
In the context of ARP learning via gratuitous ARP on Dell EMC Networking OS, the gratuitous ARP is a request. A gratuitous ARP request
is an ARP request that is not needed according to the ARP specication, but one that hosts may send to:
• detect IP address conicts
• 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 change
In the request, the host uses its own IP address in the Sender Protocol Address and Target Protocol Address elds.
Enabling ARP Learning via Gratuitous ARP
To enable ARP learning via gratuitous ARP, use the following command.
• Enable ARP learning via gratuitous ARP.
CONFIGURATION mode
arp learn-enable
ARP Learning via ARP Request
In Dell EMC Networking OS versions prior to 8.3.1.0, Dell EMC Networking OS learns via ARP requests only if the target IP specied in the
packet matches the IP address of the receiving router interface. This is the case when a host is attempting to resolve the gateway address.
If the target IP does not match the incoming interface, the packet is dropped. If there is an existing entry for the requesting host, it is
updated.
IPv4 Routing
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