— address resolution display and
||-s hostname ether_addr
||-S hostname ether_addr
utility displays and modifies the Internet-to-Ethernet
address translation tables used by the address resolution protocol
). With no flags, the program displays the current
ARP entry for hostname
. The host may be specified by
name or by number, using Internet dot notation.
- The program displays or deletes all of the current ARP
- A super-user may delete an entry for the host called
hostname with the -d flag. If the
pub keyword is specified, only the
“published” ARP entry for this host will be deleted.
Alternatively, the -d flag may be combined with the
-a flag to delete all entries.
- Limit the operation scope to the ARP entries on
interface. Applicable only to the following
operations: display one, display all, delete all.
- Show network addresses as numbers (normally
arp attempts to display addresses symbolically).
- 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. In this case the ether_addr can be given as
auto in which case the interfaces on this host will be
examined, and if one of them is found to occupy the same subnet, its
Ethernet address will be used. If the only keyword is
also specified, this will create a “published (proxy only)”
entry. This type of entry is created automatically if
arp detects that a routing table entry for
hostname already exists.
If the reject keyword is specified the entry will be
marked so that traffic to the host will be discarded and the sender will
be notified the host is unreachable. The blackhole
keyword is similar in that traffic is discarded but the sender is not
notified. These can be used to block external traffic to a host without
using a firewall.
- Is just like -s except any existing ARP
entry for this host will be deleted first.
- Cause 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
with argument meanings as given above. Leading whitespace and empty lines
are ignored. A ‘
#’ character will mark
the rest of the line as a comment.
utility appeared in