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.


[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 :
  Default TTL     : 64
  Arp Age         : 1000
  Domain Suffix   : DNS server     :
  VLAN                 | IP Config  IP Address     Subnet Mask      Proxy ARP
  -------------------- + ---------- --------------- --------------- ---------
  DEFAULT_VLAN         | Manual    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 
ip arp-age 1000
snmp-server community "public" Unrestricted 
snmp-server host "public"
vlan 1
   name "DEFAULT_VLAN"
   untagged B1-B24,C1-C24,D1-D24
   ip address