If some other machine wants to communicate with some second other machine ... say secmachine.homenet.com it connects to the DNS server of homenet.com. (This step won't be done if IP addresses are in use.
The DNS server then sends the IP address to firstmachine.homenet.com or firstmachine uses the known one. Next firstmachine will broadcast an "ARP whois ip.of.sec.srv" request. sec.srv or secmachine will answer with an ARP reply which contains the IP and the MAC address. Firstmachine then initiates the communication using this MAC address. Don't forget. The transport layer is ETHERNET. There don't exist IP addresses. Just for clarification. arp will do exactly this and arpd can even collect such information because every machine on a subnet will see all of the requests and replies. Regards Frank On Wed, 2005-08-31 at 05:50 -0500, John Jolet wrote: > On Aug 31, 2005, at 1:38 AM, Frank Schafer wrote: > > > > > ... what about arp? > > > > If this machine has the mac address listed on the outside of the > case, or he opens it up to look at the card, sure. if you don't know > what the mac address is....then you're stuck. Of course, if it's a > small, home network, you could always just turn off all the other > computers except that one and the one you're on and ask the router > who's connected. be quicker just to launch nmap and go get some coffee. -- gentoo-user@gentoo.org mailing list
