IBM Bridge/ Heritage, User Manual

Page: 85 / 167

7-20
Command Sets for Command Line Interface
1. arp
Syntax:
arp add <i/f> <IP address> <MAC address>
arp delete <i/f> <IP address>
arp flush
arp [list]
arp help [all|<cmd>]
Description:
Allows display and manipulation of the ARP table: the list of IP
addresses and corresponding MAC addresses obtained by ARP on
Ethernet-like interfaces. Normally there is no need to add entries to
the table with “
arp add
”, since they should be discovered by the
ARP protocol. Displaying the table with “
arp list
” (or just “
arp
”)
is sometimes useful, and deleting an entry with “
arp delete
”, or the
whole table with “
arp flush
”, can sometimes speed up recovery
from temporary problems if something unusual has happened.
Entries added with “
arp add
” do not time out like those discovered
by use of the ARP protocol, but they are deleted by “
arp flush
” and
will not survive a restart (they are not saved by configuration saving).
Note that the ARP table is used only for destinations on directly
connected Ethernet-like networks, not for those reached through
routers (although the ARP table may be used to discover the MAC
address of the router).
Example:
DSL>
ip arp add ether 192.168.50.1 8:0:20:19:9A:D9
DSL>
ip arp
arp add flane 192.168.2.63 00:20:2b:e0:03:87 # 8m58s
arp add flane 192.168.2.109 00:20:2b:03:08:b1 # 2m24s
arp add ether 192.168.50.1 08:00:20:19:9a:d9 # forever
arp add ether 192.168.50.57 00:20:af:2e:fa:3c # 3m25s
DSL>
ip arp delete flane 192.168.2.109
DSL>
ip arp list
arp add flane 192.168.2.63 00:20:2b:e0:03:87 # 8m46s
arp add ether 192.168.50.1 08:00:20:19:9a:d9 # forever
arp add ether 192.168.50.57 00:20:af:2e:fa:3c # 3m13s
DSL>
ip arp flush
DSL>
ip arp
# flane ARP table is empty
# ether ARP table is empty
DSL>
ip arp
arp add flane 192.168.2.108 00:20:2b:03:0a:72 # 10m58s
# ether ARP table is empty
(The last example shows that the MAC address for 192.168.2.108 has