ARP age timer

The 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. For more information on ARP, see IP tables and caches.

You can increase the ARP age timeout maximum to 24 hours or more with this command:

Syntax:


ip arp-age <[1...1440]|infinite>
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.

Default: 20 minutes

Setting the ARP age time out to 1000 minutes

switch(config)# ip arp-age 1000

To view the value of ARP age timer, enter the show ip command. The Arp Age time value is bold as shown in following example.

The show ip command displaying ARP age

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

You can also view the value of the ARP age timer in the configuration file. The ip arp-age 1000 value is bold as shown in following example.

The ip arp-age value in the running config file

switch(config)# show running-config

Running configuration:

; J9627A Configuration Editor; Created on release #XX.15.XX
; Ver #01:01:00

hostname "Switch"
savepower led
mirror-port 7
stack commander "TEST_STACK"
stack member 1 mac-address 0024A8D13A40
ip arp-age 100
vlan 1
   name "DEFAULT_VLAN"
   untagged 1-28
   ip address dhcp-bootp
   exit
vlan 222
   name "VLAN222"
   no ip address
   exit
snmp-server community "public" unrestricted
snmp-server host 16.181.51.82 community "public"

ARP Age value

===========================- TELNET - MANAGER MODE ======================
                  Switch Configuration - Internet (IP) Service

  IP Routing : Disabled

  Default Gateway : 15.255.120.1
  Default TTL     : 64
  Arp Age         : 1000

  IP Config [Manual] : Manual

  IP Address  : 15.255.111.11
  Subnet Mask : 255.255.248.0

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