NAME

arp − address resolution display and control

SYNOPSIS

arp hostname
arp −a [ entire ]
arp −d hostname
arp −s hostname ether_addr [ temp ] [ publ ]
arp −f filename

DESCRIPTION

The arp program displays and modifies the Internet-to-Ethernet address translation tables used by the address resolution protocol [arp(7P)]. 

With no flags, the program displays the current ARP entry for hostname.  With the −a flag, the program displays all the current ARP entries by requesting the ith entry from the EXOS 8010 board until an error is returned.  Normally, only those entries for which corresponding hosts can be found are displayed.  However, by specifying entire the entire contents of the ARP table are displayed. 

With the −d flag, super user can delete an entry for the host called hostname. 

The −s flag creates an ARP entry for the host called hostname with the Ethernet address ether_addr.  The Ethernet address is given as six hexadecimal bytes separated by colons.  Alternatively, each of the six bytes may be specified in octal, decimal or hexadecimal, and separated by dots.  In this case, octal numbers start with 0, decimal numbers start with 1 to 9, and hexadecimal numbers start with 0x or 0X.  The entry will be permanent unless the option temp is given in the command.  Permanent entries do not age out of the cache and are given preference to remain in the cache when the table overflows.  If the option publ is given, the entry is “published”; that is, this system will respond to ARP requests for hostname even though the host name is not its own.  Once again, only the super user can alter the contents of the ARP cache. 

The −f flag causes the file filename to be read and multiple entries to be set in the ARP tables.  Entries in the file should be of the form

hostname ether_addr [ temp ] [ publ ]

with argument meanings and formats as given above. 

DIAGNOSTICS

The ARP command will complain of errors in its input format, of non-super users attempting to update the cache, of references to unknown hosts, and of various system-detected errors. 

SEE ALSO

arp(7P)

Version 2.4  —  May 08, 1986