IPv4 Routing | 267
In FTOS, proxy ARP enables hosts with knowledge of the network to accept and forward packets from 
hosts that contain no knowledge of the network. Proxy ARP makes it possible for hosts to be ignorant of 
the network, including subnetting.
For more information about proxy ARP, refer to RFC 925, 
Multi-LAN Address Resolution, and RFC 
1027, 
Using ARP to Implement Transparent Subnet Gateways.
Configuration Task List for ARP
The following list includes configuration tasks for ARP:
• Configure Static ARP Entries (optional)
• Enable Proxy ARP (optional)
• Clear ARP Cache (optional)
• ARP Learning via Gratuitous ARP
• ARP Learning via ARP Request
• Configurable ARP Retries
For a complete listing of all ARP-related commands, refer to the FTOS Command Line Reference Guide.
Configure Static ARP Entries
ARP dynamically maps MAC and IP addresses, and while most network host support dynamic mapping, 
you can configure an ARP entry (called a static ARP) for the ARP cache. 
To configure a static ARP entry, use the following command in CONFIGURATION mode:
These entries do not age and can only be removed manually. To remove a static ARP entry, use the 
no arp 
ip-address 
command syntax.
Command Syntax Command Mode Purpose
arp ip-address mac-address interface  CONFIGURATION  Configure an IP address and MAC address mapping 
for an interface.
• ip-address: IP address in dotted decimal format 
(A.B.C.D).
• mac-address: MAC address in nnnn.nnnn.nnnn 
format
• interface: enter the interface type slot/port 
information.