Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In most home routers, you can find a DHCP client table. Obviously the router knows the IP and MAC addresses of the connected computers. However, most of the time the router can list the computer names as well. So what protocol do they use to get the names? Perhaps NetBIOS?

share|improve this question
up vote 3 down vote accepted

The protocol the routers use is DHCP itself. Looking at this breakdown of the protocol messages, you can see that in the DHCPDISCOVER message, which is the message a client sends to request a DHCP IP, it contains a Server Host Name field, which contains the clients hostname.

share|improve this answer
Oh thanks, I didn't know DHCPDISCOVER has such a field. Now I'm wondering why I can't see the hostname of my Ubuntu boxes in my router. Maybe I need WireShark to check what's going on. – netvope Mar 12 '10 at 1:19

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.