7.3. ARP

To configure state timeouts for Neighbor Cache entry, use the following commands. Three states are used in the vCGNAT ARP-table: INCOMPLETE, REACHABLE and STALE (see RFC 4861#section-7.3.2):

ip neighbor timeout reachable (1-604800000)

Set timeout for REACHABLE state in milliseconds. The set value is multiplied by a random number in the range from 0.5 to 1.5. The default is 30000(ms) x random(0.5;1.5).

ip neighbor timeout stale (1-604800000)

Set timeout for STALE state in milliseconds. The default is 30000 ms.

To configure the period during which the router will send ARP requests to the neighbor, use the following command:

ip neighbor timeout retransmit (1-604800000)

Static ARP

Sometimes, it is necessary to configure a static entry in the ARP table. To do that, use the command:

<ip|ipv6> neighbor <A.B.C.D|X:X::X:X> interface NAME mac X:X:X:X:X:X

Set a static entry for ARP table for IPv4 or IPv6.

show <ip|ipv6> neighbor

Display ARP table.

vCGNAT01# show ip neighbor
Neighbor                                        State       Interface                       MAC address
-------------------------------------------------------------------------------------------------------------                                    Permanent   if2                             0C:C4:83:76:00:03