Adjusting the ARP Aging Timer

By default, the ARP aging timer is set at 20 minutes. In environments with many directly attached hosts, such as metro Ethernet environments, increasing the amount of time between ARP updates by configuring the ARP aging timer can improve performance.

To configure the ARP aging timer, include the aging-timer statement at the [edit system arp] hierarchy level:

[edit system arp]

aging-timer minutes;

The aging timer range is from 20 through 240 minutes. The timer value you configure takes effect as ARP entries expire. Each refreshed ARP entry receives the new timer value. The new timer value does not apply to ARP entries that exist at the time you commit the configuration.