Increasing ARP age timeout (CLI)
The address resolution protocol (ARP) age is the amount of time the switch keeps a MAC address learned through ARP in the ARP cache. The switch resets the timer to zero each time the ARP entry is refreshed and removes the entry if the timer reaches the ARP age.
Syntax:
no ip arp-age [[1...1440] | infinite]
Allows the ARP age to be set from 1 to 1440 minutes (24 hours).
If the option
infinite is configured, the internal ARP age timeout is set to 99,999,999 seconds (approximately 3.2 years). An
arp-age value of 0 (zero) is stored in the configuration file to indicate that
infinite has been configured. This value also displays with the
show commands and in the menu display (Switch Configuration IP Config).
Default: 20 minutes
Setting the ARP age timeout to 1000 minutes
switch(config)# ip arp-age 1000
Show IP command displaying ARP age
To view the value of ARP age timer, enter the
show ip command. The Arp Age time value is shown in bold below.
switch(config)# show ip Internet (IP) Service IP Routing : Disabled Default Gateway : 15.255.120.1 Default TTL : 64 Arp Age : 1000 Domain Suffix : DNS server : VLAN | IP Config IP Address Subnet Mask Proxy ARP -------------------- + ---------- --------------- --------------- --------- DEFAULT_VLAN | Manual 15.255.111.13 255.255.248.0 No
IP ARP-age value in the running config file
You can also view the value of the ARP age timer in the configuration file. The ip arp-age 1000 value is shown in bold below.
switch(config)# show running-config Running configuration: ; J9091A Configuration Editor; Created on release #K.15.XX hostname "8200LP" module 2 type J8702A module 3 type J8702A module 4 type J8702A ip default-gateway 15.255.120.1 ip arp-age 1000 snmp-server community "public" Unrestricted snmp-server host 16.180.1.240 "public" vlan 1 name "DEFAULT_VLAN" untagged B1-B24,C1-C24,D1-D24 ip address 15.255.120.85 255.255.248.0 exit gvrp spanning-tree