Setting ARP Encapsulation By default, Ethernet ARP encapsulation (represented by the arpa keyword) is enabled on an IP interface. To setting ARP encapsulation, perform this procedure: Procedure Configuring IP Unicast Routing Setting ARP Encapsulation Command or Action Purpose Device(config-if)#arp timeout 20000 which is also the default setting. However, if your network experiences regular updates to ARP cache entries, consider changing the timeout. Note that decreasing the ARP timeout can result in increased network traffic. It is not recommended to set the ARP timeout to 60 seconds or less. Step 7 end Example: Device(config)#end Returns to privileged EXEC mode.
Step 8 show interfaces [interface-id] Example: Device#show interfaces gigabitethernet 1/0/1 Verifies the type of ARP and the timeout value that is used on all interfaces or a specific interface. Step 9 show arp Example: Device#show arp Views the contents of the ARP cache. Step 10 show ip arp Example: Device#show ip arp Views the contents of the ARP cache. Step 11 copy running-config startup-config Example: Device#copy running-config startup-config (Optional) Saves your entries in the configuration file. Command or Action Purpose Step 1 enable Example: Enables privileged EXEC mode. Enter your password if prompted. Configuring IP Unicast Routing 16