User Guide

OmniAccess SafeGuard OS Administration Guide
185
Chapter 5: Setting Up SafeGuard Switches
broadcasts IP addresses and gets the MAC address as a response from the device owning
that IP.
Layer 3 devices can respond to an ARP request for the host for which it has a route. This
type of ARP response is called Proxy ARP. Even though a host is on another LAN segment
or network, the hosts behaves as if all other hosts are actually on the network. If a host
does not know the default gateway, proxy ARP can learn the first hop.
The SafeGuard Switch has an ARP cache to store IP addresses and MAC addresses so that
it does not need to broadcast to locate local devices. ARP entries are created either
statically or dynamically and stored in the cache. Static entries are added manually to the
cache table for a device and kept in the cache permanently. Dynamic entries are added to
the cache by the system as the result of previous ARP requests being successfully
completed. Dynamic entries are aged-out periodically to limit the size of the cache.
ARP and proxy ARP are enabled by default. The following sections describe the
configuration options for ARP:
■ Creating a Static ARP entry
■ Setting the ARP Cache Size
■ Enabling or Disabling Proxy ARP
■ Controlling ARP Renewals
■ Setting the ARP Response Time
■ Setting the Retry Limit
■ Changing the ARP Timer
■ Clearing the ARP Cache
Creating a Static ARP entry
To create a static ARP entry, use the arp command in Global Configuration mode. Use the
no version of the command to discard the entry.
arp ipaddr macaddr
no arp
ipaddr macaddr
Syntax Description ipaddr Specifies the IP address of a device on a
subnet attached to an existing routing
interface.