Windows XP Pro update error

[iCE]

Hey all, I have kind of a complicated question. I work for a ISP in Canada, a cable company. I do 2nd level tech support and I am totally stumped. I know there is allot of knowledge here. Here's the issue. I spoke with a customer yesterday for a hour trying to get him online. The problem is that he could not pull a IP address. I had verified that the DHCP was sending one out but there was no ACK from the PC. So we are sending a IP out. We tried on 2 pc's one desktop and one laptop. Both the same thing, just gave the standard DCHP error and then had the 169.x.x.x IP. He also had a router so we pluged that into the cable modem and that pulled a IP address no problem. He pluged his laptop into the router and it could still not pull a IP? So I know it's the system for sure as both pc's could not pull a IP from the router. So in trying to figure out WTF is going on I had him change is NIC MAC to the same as the router and then hooked it back up to the cable modem and then it got a IP and he was online. So it seems that by changing the NIC MAC fixes the issue? But the kicker is why? why would you have to change the nic mac to get a IP? On the desktop we changed the nic mac by 1 hex and it worked fine after that. So here's what I think the issue is and I need help to verify this. I am thinking that there has been a recent with in the last 2 or 3 weeks a Microsoft update that is doing something to either make the NIC MAC invalid or corrupt? I had gone through everything with this person. Even ran the netsh command to reset tcp/ip. Also tried to reinstall the NIC and the ipconfig /flushdns as well as that sometimes get's things going. But I am at a loss about this one and I am starting to see this come up more often with other customers? If anyone has any ideas it would be greatly apreciated. Also if anyone knows how to see the list of updates released with in the past 30 days would be a big help as well.

Thank you,

iCE

[ronenuos]

I was going to say it sounds like his router/firewall/proxy is misconfigured but I am not so sure now. The only way it *could* be a windows update issue is to find out if he had ALL his PCs up to date (most people don't, though the auto update will do it).

Since it's limited to his LAN my money goes on a router/windows config problem on his end...I could be way off though.

I didn't know you could change the MAC address to anything, I always thought that was in the firmware (I guess your ISP can if they make the NIC?) either way I am up to date, my NIC, Router & Modem all have unique MAC addresses so not sure what the conflict is...we may never know :(

[iCE]

Yes if you are using Windows 2000 or XP you can change the NIC mac. But that IS what the problem is. If I get them to change it then it works fine. But why would it not work with the old NIC MAC? I mean it a unique one or else I would see a IP address going to a NIC and it's Pingable from our end but he is getting a 169.x.x.x

No routers are involved. And if they have a router it's not a issue as Microsoft can't update your router firmware and screw that up on you too. And I am positive that it's a Windows update causing this as it has come on all of a sudden. And when you start getting more and more people calling in and telling you the same thing and you try everything you can think of and it doesn't work execpt changeing the NIC MAC then it is something on the PC end but WHAT is the question.

[ronenuos]

Yes if you are using Windows 2000 or XP you can change the NIC mac. But that IS what the problem is. If I get them to change it then it works fine. But why would it not work with the old NIC MAC? I mean it a unique one or else I would see a IP address going to a NIC and it's Pingable from our end but he is getting a 169.x.x.x

No routers are involved. And if they have a router it's not a issue as Microsoft can't update your router firmware and screw that up on you too. And I am positive that it's a Windows update causing this as it has come on all of a sudden. And when you start getting more and more people calling in and telling you the same thing and you try everything you can think of and it doesn't work execpt changeing the NIC MAC then it is something on the PC end but WHAT is the question.

I agree there is NO reason anyone has to change their NIC MAC address, I have cable and no probs there. I disagree with you about the router though, if he is using a router it could be a problem if he has it all misconfigured (i.e. my ISP won't support it, they make me disconnect the router/firewall when I ask for tech support) so that could be the problem, but it doesn't sound like it is.

It wouldn't be the first time MS updates caused some kind of conflicts so that's very possible, try calling them and reporting it to hem they're pretty good with that stuff esp. if HEAPS of people are getting this like you said.