Foundry NetIron M2404C and M2404F Metro Access Switches
Switch Administration (Rev. 03)
Managing the ARP Table © 2008 Foundry Networks, Inc.
Page 20 of 87
NOTE
A static CPU cache has been implemented where static MAC entries, defined
using the
ip arp
command, are stored. The application software will first look up in
this static CPU cache before looking up in the cache containing dynamic MAC
entries.
Command Syntax
device-name
#
show ip arp
Example
device-name
#
show ip arp
===+==================+=================+========+========+=========+
# | IP Address | MAC |Age(min)| if | Type |
---+------------------+-----------------+--------+--------+---------+
0 | 10.0.0.10 |00:00:00:00:00:10| 0 | sw0 | Static |
Setting the ARP Overwriting Data Timer
The
fib arp-overwrite
command, in Global Configuration mode, sets the ARP overwriting data
timer. The
no
form of the command resets the ARP overwriting data timer to its default value.
The ARP table is updated at periodic time intervals. ARP updates are not accepted within each
interval. For example, if the timer is set to 9 seconds, ARP updates are received once every 9
seconds. You can use the
fib arp-overwrite
command to change the ARP table update periods. If
the user sets the timer to zero (0), the ARP entry will be updated by each new packet.
NOTE
Removing ARP-overwriting protection (setting the ARP overwrite timer to zero)
will overload the CPU in case of ARP flooding.
To view the ARP table entries, use the
show ip arp
command in Privileged (Enable) mode.
By default, the ARP overwriting data timer is set to 20 seconds.
Command Syntax
device-name
(config)#
fib arp-overwrite timer <time>
device-name
(config)#
no fib arp-overwrite
Argument Description
time
Sets the time in seconds, in the range <0-20>. Setting the timer to zero (0) disables
this protection.