ARP messages

[savik2]

Please can someone tell me what ARP messages are?

[j2buttonsw]

On a computer network using the TCP/IP networking protocol, ARP (address resulution protocol) is used to map the IP address of a network card to its burnt-in unique MAC (machine acccess code) address. This info is stored on the computer as an ARP cache and you can query this. The IP address is expressed as 4 blocks of numbers ranging from 0-255 (eg 192.168.0.250) whereas the MAC address is expressed as a 48 bit hexadecimal value (eg 00 00 0C 8A 12 B3).

[savik2]

Thanks, j2 - now what I need to know is why outsiders would want to do this. There is, apparently, a huge amount of ARP traffic being generated by virus-infected users - have been told it is not threatening, but it's certainly keeping my modem busy!