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TOPIC: IP Address Conflict

IP Address Conflict 12 years 9 months ago #14335

  • gainil
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Hi Guys!!

I hope I am posting in a proper forum.

Today I faced a very wierd problem, I have a small network of around 70 pc's (XP/2k/98) with no DHCP, no ADS. Allmost all the machines on my network started giving "Ip Conflict" message. I have a LinkSys WAP54G Wireless Access Point (it too dosent have DHCP enabled), I switched if off and the problem stoped, I turned it on and the problem started again. Later on I switched it off for 30 mins and started it again, by that time everything was fine. Now too everything is working fine. I checked eventlog of machines with "Ip Conflict" error and found 2 MAC address.

Now can any one help me in this regards?? Aslo some one can tell me, how to find out the MAC (Physical) address of all the machines on my network from a single machine.

Thanks and Regards to all

IP Address 12 years 9 months ago #14337

I've had a similar thing that I also never quite got to the bottom of because it went away! It soundls like something is upsetting the ARP caches on your network. Routers maintain ARP caches and probably your wireless device as well.
As to finding the MAC addresses all you need is a simple audit tool, something like

Re: IP Address Conflict 12 years 9 months ago #14338

Oops, posted too quickly! Also meant to add that if you want something to monitor the ARP cache on your PCs have a look at

me too! 12 years 9 months ago #14494

  • Kn1ght
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I too am having this exact same problem it is when I plug in a linksys wireless range extender and when I unplug it the wireless computers are fine, but when I plug it in boom it gives me IP conflict. It is driving me nuts. Any ideas?

Darn WAP54G 9 years 9 months ago #30328

I, too, ran into the anomaly of every PC on my network getting IP address conflicts. I jotted down the MAC address and found that it was the same MAC on all my computers that was causing the problem.

It was crippling our network. No internet, no email, and intermittent access to local resources. My boss did a lookup on the MAC address and found that it was a CISCO/Linksys registered vendor address.

We only have a handful of CISCO/Linksys devices so it was easy to track down. We found it to be one of the WAP54G that we had set in bridge mode. We have a WYSE terminal connected to the WAP54G to connect to the network wirelessly. The WYSE device was unplugged. I unplugged the WAP54G and the IP conflicts disappeared. I then plugged the WYSE and WAP54G back in and the terminal device came right up and connected just fine. No IP conflicts.

I didn't have time for testing to see if it would happen again if I unplugged the WYSE. I'll have to do it in the off hours so I don't nuke the network again.

Very strange don't you think?
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