NAME

arp − address resolution display and control

SYNOPSIS

arp [ -i interface ] hostname
arp [ -i interface ] -a [ unix ] [ kmem ]
arp [ -i interface ] -d hostname
arp [ -i interface ] -s hostname ether_addr [ temp ] [ pub ] [ trail ]
arp [ -i interface ] -f filename
arp [ -i interface ] -e filename

DESCRIPTION

The arp program displays and modifies the Internet-to-Ethernet address translation tables used by the address resolution protocol (arp(4P)). 

The interface parameter is used in configurations with intelligent networking controllers to specify a particular controller or the host based protocols.  If interface is specified as host, the address translation tables for the host based networking interfaces are used.  Otherwise interface specifies an intelligent controller name such as iph0 and the tables on that controller are affected.  If this parameter is omitted, then the host-based address translation tables and those on all intelligent controllers configured are used. 

With no other flags, the program displays the current ARP entry for hostname.  The host may be specified by name or by number, using Internet dot notation.  With the -a flag, the program displays all of the current ARP entries by reading the table from the file kmem (default /dev/kmem) based on the kernel file unix (default /unix). 

With the -d flag, a super-user may delete an entry for the host called hostname. 

The -s flag is given to create an ARP entry for the host called hostname with the Ethernet address ether_addr.  The Ethernet address is given as six hex bytes separated by colons.  The entry will be permanent unless the word temp is given in the command.  If the word pub is given, the entry will be "published"; i.e., this system will act as an ARP server, responding to requests for hostname even though the host address is not its own.  The word trail indicates that trailer encapsulations may be sent to this host. 

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 ] [ pub ] [ trail ]

with argument meanings as given above. 

The -e 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

ether_addr hostname [ temp ] [ pub ] [ trail ]

with argument meanings as given above.  Note that this flag is the same as the -f flag except that the first two fields in the file to be read are reversed.  This format is suitable for reading the /etc/ethers file used by the yellow pages. 

SEE ALSO

inet(3N), arp(4P), ethers(4), ifconfig(1M)

CX/UX Networking