IP address conflict

"Don Harvey" wrote in news:pw9ke.268$ snipped-for-privacy@tornado.rdc-kc.rr.com:

You do IPconfig /all on the machines at the Command Prompt and get the MAC/Hardware address of the NIC(s) being used on your network.

You go to the router logs to see what IP(s) have been issued to what NIC MAC(s).

If you have a MAC listed in the router logs that is not one of the NIC MAC (s) for one of your machines, then someone could be using your wireless network. That is a possibility.

The IP conflict means one of your machines cannot get an IP from the router and another machine on the network is already using that IP.

The DHCP server on the router uses the NIC(s) MAC to assigning the same IP to the NIC and most of the time that IP assignment stays permanent in a two machine setup like you have for your network.

You can also delete the NIC MAC(s) out of the MAC Table and get a fresh start and see what happens too.

Duane :)

Many thanks Duane, this helps a lot. Will check it tonight when I get home. This just started a few days ago and I did not have a clue on where to begin.

: > Any idea on how to track this down. : >

: : You do IPconfig /all on the machines at the Command Prompt and get the : MAC/Hardware address of the NIC(s) being used on your network. : : You go to the router logs to see what IP(s) have been issued to what NIC : MAC(s). : : If you have a MAC listed in the router logs that is not one of the NIC MAC : (s) for one of your machines, then someone could be using your wireless : network. That is a possibility. : : The IP conflict means one of your machines cannot get an IP from the router : and another machine on the network is already using that IP. : : The DHCP server on the router uses the NIC(s) MAC to assigning the same IP : to the NIC and most of the time that IP assignment stays permanent in a two : machine setup like you have for your network. : :

: You can also delete the NIC MAC(s) out of the MAC Table and get a fresh : start and see what happens too. : : Duane :) :

Two of your computers have the same IP address. Type IPCONFIG into a command prompt window on each of them, and change the IP for one of the offending machines.

If none of your machines has a duplicate IP, then its possible you have an intruder on your wireless network, who is cloning one of your machine's MAC addresses so he can get an IP from your router. Next time you see the problem, see what the router thinks is connected, and consider more security.

Thanks Mark and Duane

It has not occurred t>