Laptop with WinXP wont work with cable modem.

[Giscardo]

Hi, I live in Berkeley, and I use AT&T broadband cable modem on my desktop, for about a year now. My roomate just got a compaq armada e500, and installed windows XP on there. We plugged the ethernet card from his laptop to my cable modem, and windowsxp on his notebook recognized a network connection and brought up a little network connection icon in the system tray. Cool, we thought it was working at this point. But there was no internet access, no AIM, and no web. I tried to ping www.anandtech.com and that didn't work.
So I right click on the network icon in the systray, and then click on status. Under the IP address it shows some weird IP, which isn't what my IP is. I think it's weird cause we set up the notebook to obtain IP automatically. One of my friends thinks the problem is that the cable modem will only work with my NIC (he thinks the cable company has taken note of my NIC's mac address). Just so you guys know, my roomate was using this laptop to connect with his brother's DSL service at his brother's house for a while, so that's where i suspect it is getting the weird IP address that starts with 169 (mine starts with 12). So in my attempt to get it to work I removed the network card under device manager and got it to re-detect it, and reinstall the drivers automatically. THen i set up the network again. All the settings on his laptop having to do with internet and network are the same as on my desktop.
Also, this info might help you guys troubleshoot:
1. When he used the laptop with his bro's DSL, he said that sometimes it didn't work, and he would fix it by right clicking on the connection and disabling it, then he'd enable it again to get it to work.
2. After I gave up on trying to get it to work with my cable modem, i plugged my coputer back into the cable modem. Then i couldn't use my internet for a few minutes. He said that happened with his brother's DSL too, that his laptop would screw with the connection.

Just trying to give you guys all the info, cause I don't know much about networks, so I can't interpret what any of this means myself.

 

[Heisenberg]

I don't know for sure b/c I don't have AT&T cable but its possible the modem is locked to your NIC's MAC address. The only other thing you
could try is to plug in the laptop to the modem, and then power cycle the modem (completely unplug it, don't just turn it off). After it comes back on, do Start>Run, then type "cmd".
In the window it opens, type "ipconfig /renew" and see what happens. Even if that makes it work, you're still gonna need a better way to
share the connection.

 

[SCSIfreek]

did you disable firewall in XP? might want to try that. Also sometimes AT&T takes couple minutes to re-assign a IP address especially now that is DHCP. If you want get a router and stay with that IP forever


--SCSI

 

[miguel]

Seems like you weren't able to connect with a DHCP server. The "weird" IP is like a 169.x.x.x or something, right? Probably your mac address is registered, so you have to let them know another PC is using the cable modem now.

 

[Giscardo]

Yeah, the "weird" IP is 169.x.x.x. And I did disable the firewall in XP on his laptop still didn't work. I'm convinced that the cable will only work with the mac address of my desktop. Is there any software to spoof my mac address on his laptop as a temporary measure?

 

[MWalkden]

I take it from what you said you getting an IP automatically from your ISP (AT&T). Your problem is the computer name. It has to be that c1234567-a.bla.bla.home.

The problem with the DSL at the brothers house depends on how he is connecting. If it is through a firewall (NAT or otherwise) then I have to ask if he runs it on a domain anywhere else or has a primary DSN suffix listed (not exactly sure where that might be in XP, but My Computer properties, network settings, more will get you there in 2K). If so, removing the DNS suffix will solve the problem on his brothers DSL. It could be other things too.

.(MW)