Managing The Arp Table; Monitoring 5399 Rac Activity - Nortel 5399 User Manual

Chapter 1 Network Administration

Managing the ARP Table

Monitoring 5399 RAC Activity

Model 5399 Remote Access Concentrator Network Administrator's Guide for UNIX
A-32
The Address Resolution Protocol (ARP) maps Internet addresses to
hardware addresses. Hosts implementing ARP maintain a translation
table for these address mappings. When an 5399 RAC receives a request
for a host that does not have a translation entry in the ARP table, it
broadcasts for the hardware address. The superuser CLI arp command
displays and modifies entries in this translation table.
Since the 5399 RAC automatically builds the ARP table dynamically, you
rarely need to modify the table. You can use arp to modify the table for
hosts that do not implement ARP, enabling communications between the
host and the 5399 RAC. Using arp, you can delete a specified entry
and/or create an entry for a host.
A created entry is permanent unless it is defined as temporary, in which
case the entry is deleted after 20 minutes. An entry defined as published
causes the 5399 RAC to respond with its hardware address for the
specified host, even though the IP address is not the 5399's. Publishing
a hardware address for another host frequently is done to route data to a
host connected to the 5399 RAC through a SLIP or PPP link.
The CLI commands assist in monitoring 5399 RAC activities (see Using
the CLI Commands on page A-113 for more information). These activities
include:
• Logging user and 5399 RAC activities.
• Displaying user activity.
• Displaying 5399 RAC statistics.
• Monitoring port activity.
Book A