Cisco Systems 3750E manual Set ARP Encapsulation, 38-11

Chapter 38 Configuring IP Unicast Routing

Configuring IP Addressing

	Command	Purpose
Step 3
	arp ip-address hardware-address type [alias]	(Optional) Specify that the switch respond to ARP requests as if
		it were the owner of the specified IP address.
Step 4
	interface interface-id	Enter interface configuration mode, and specify the interface to
		configure.
Step 5
	arp timeout seconds	(Optional) Set the length of time an ARP cache entry will stay in
		the cache. The default is 14400 seconds (4 hours). The range is
		0 to 2147483 seconds.
Step 6
	end	Return to privileged EXEC mode.
Step 7
	show interfaces [interface-id]	Verify the type of ARP and the timeout value used on all
		interfaces or a specific interface.
Step 8
	show arp	View the contents of the ARP cache.
	or
	show ip arp
Step 9
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To remove an entry from the ARP cache, use the no arp ip-addresshardware-address type global configuration command. To remove all nonstatic entries from the ARP cache, use the clear arp-cacheprivileged EXEC command.

Set ARP Encapsulation

By default, Ethernet ARP encapsulation (represented by the arpa keyword) is enabled on an IP interface. You can change the encapsulation methods to SNAP if required by your network.

Beginning in privileged EXEC mode, follow these steps to specify the ARP encapsulation type:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface interface-id	Enter interface configuration mode, and specify the Layer 3
		interface to configure.
Step 3
	arp {arpa snap}	Specify the ARP encapsulation method:
		• arpa—Address Resolution Protocol
		• snap—Subnetwork Address Protocol
Step 4
	end	Return to privileged EXEC mode.
Step 5
	show interfaces [interface-id]	Verify ARP encapsulation configuration on all interfaces or
		the specified interface.
Step 6
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable an encapsulation type, use the no arp arpa or no arp snap interface configuration command.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		38-11