Linux in a Nutshell, 6th Edition

Name

arp

Synopsis

arp [options]

TCP/IP command. Clear, add to, or dump the kernel’s Address Resolution Protocol (ARP) cache (/proc/net/arp). ARP is used to translate protocol addresses to hardware interface addresses. Modifying your ARP cache can change which interfaces handle specific requests. ARP cache entries may be marked with the following flags: C (complete), M (permanent), and P (publish). While arp can create a proxy for a single system, subnet proxies are now handled by the arp kernel module, arp(7). See the “Linux Advanced Routing & Traffic Control HOWTO” for details.

Options

host option arguments may be given as either a hostname or an IP address. With the -D option, they may also be given as a hardware interface address (e.g., eth0, eth1).

-a [hosts], --all [hosts]

Display entries in alternate (BSD) style for hosts or, if none are specified, all entries.

-d host [pub], --delete host [pub]

Remove the specified host’s entry. To delete a proxy entry, add the pub argument and specify the interface associated with the proxy using -i.

-D, --use-device

Use the hardware address associated with the specified interface. This may be used with -s when creating a proxy entry.

-e

Display entries in default (Linux) style.

-f file, --file file

Read entries from file and add them.

-H type, --hw-type type, -t type

Search for type entries when examining the ARP cache. type is usually ether (Ethernet), which is the default, but may be ax25 (AX.25 packet radio), arcnet (ARCnet), pronet (PROnet), or netrom ...