|
|
This command shows the contents of a router's Address Resolution Protocol cache. This cache holds the mapping between a high-level protocol address and the physical address. The physical address may be either an IEEE Ethernet address, SMDS station address or a Frame Relay DLCI which can be converted into a Frame Relay Q.922 hardware address. ARP entries are added to the cache either dynamically through the use of ARP on an Ethernet LAN, SMDS Wan or IARP (Inverse ARP) on Frame Relay. They also may be added statically with the add arp command.
show arpThe information shown is:
B# | This is the hash bucket number of the cache entry. Hashing is used to index the cache to allow fast searching for an entry. |
Protocol | This identifies the high-level protocol address in the entry. The possible protocol represented in the cache are IP, AppleTalk and IPX (only on Frame Relay). |
Address | This is the high-level protocol address. IP addresses are shown in dotted-decimal notation. AppleTalk addresses are shown as net:node. IPX addresses, only on Frame Relay interfaces, are also show as net:node. |
Age | This is the age of the ARP entry in minutes. After 20 minutes the entry is timed out and deleted. Entries added statically or through IARP on Frame Relay aren't aged and will always have an age of zero. |
Hardware Addr | This is the physical address that the high-level address resolves to. If the entry is an IEEE Ethernet hardware address, it is shown with six octets separated by colons. If the entry is an SMDS station address, it is shown with 8 octets separated by dots. If the physical address is from a Frame Relay interface, it will be displayed as a DLCI address.The hardware address will sometimes report "incomplete" if there is a misconfiguration of the physical address or of the hardware itself. These age out after two minutes. |
Interface | This is the router's interface through which the hardware address can be reached. |
The following is output from the show arp command:
B# Protocol Address Age Hardware Addr Type Interface 0 IP 198.41.9.1 0 aa:00:04:00:0d:04 Dynam Ethernet A 13 IP 198.41.8.1 0 c303.444.9531 Dynam Wan0 14 IP 198.41.9.12 0 00:00:a5:2f:20:00 Dynam Ethernet A 15 IP 198.41.9.30 0 08:00:20:08:cc:0d Dynam Ethernet A
| Command | Description |
|---|---|
add ip arp | Adds a static IP ARP cache entry |
reset arp | Deletes ARP table entries |
Posted: Wed Sep 27 11:42:24 PDT 2000
Copyright 1989-2000©Cisco Systems Inc.