Arp Purge; Arp Resptime - NETGEAR M6100 Series Reference Manual

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 disabled
Format
arp dynamicrenew
Mode Privileged EXEC
no arp dynamicrenew
This command prevents dynamic ARP entries from renewing when they age out.
Format
no arp dynamicrenew
Mode 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.
Format
arp purge ipaddr
Mode Privileged EXEC

arp resptime

This command configures the ARP request response time-out.
The value for is a valid positive integer, which represents the IP ARP entry response
seconds
time-out time in seconds. The range for second
Default 1
Format
arp resptime seconds
Mode Global Config
M6100 Series Switches
is between 1-10 seconds.
s
Routing Commands
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