The Arp Command

The arp command will display internet to ethernet (IP to MAC) address translations which is normally handled by the arp protocol. When the hostname is the only parameter, this command will display the currect ARP entry for that hostname.

Usage:   arp hostname

Switches:     -a            Displays current ARP entries by interrogating the current

                                          protocol data.  If inet_addr is specified, the IP and Physical

                                          addresses for only the specified computer are displayed.  If

                                          more than one network interface uses ARP, entries for each ARP

                                          table are displayed.

                  -g            Same as -a.

                  inet_addr     Specifies an internet address.

                  -N if_addr    Displays the ARP entries for the network interface specified

                                                by if_addr.

                  -d               Deletes the host specified by inet_addr.

                  -s            Adds the host and associates the Internet address inet_addr

                                         with the Physical address eth_addr.  The Physical address is

                                          given as 6 hexadecimal bytes separated by hyphens. The entry

                                         is permanent.

                  eth_addr      Specifies a physical address.

                  if_addr       If present, this specifies the Internet address of the

                                              interface whose address translation table should be modified.

                                              If not present, the first applicable interface will be used.