Simple networking problem, or is it?

[AgentDib]

I'm dealing with a very straightforward Ethernet PCI Card -> Motorola Cable Modem -> Comcast Cable setup. Unfortunately, Windows XP Pro seems to be having an unusually high amount of difficulty automatically obtaining an IP address. The computer in question had no difficulty previously as part of a wireless network with a router, but I needed to swap PCI cards and move it to a seperate wired network.

The connection shows as Connected in Network Connections, but the computer is unable to access the internet through the cable modem. Everything is set to Automatic in TCP/IP Properties. Strangely to me, Ipconfig /release /renew is giving me IP - 192.168.100.4 - yet I am not using a router. I've powered the cable modem down for 5 minute intervals and re-installed the TCP/IP protocol with no success on either count.

Unless I'm overlooking something easy, it appears to me that Windows is confused and is automatically trying to assign an IP to the computer as if it was using a router when that is not the case. Searches on this have turned up empty, however, so I'm hoping that I'm simply omitting something important here or somebody else has experienced this.

 

[MarkLuvsCS]

Actually that doesn't seem too strange at all. The Motorola Surfboard cable modem likely is running DHCP, and thus acting as a router for your computer. 192.168.100.1 is typical for logging into the Motorola surfboard modems configuration page. As too the issue of being unable to connect, I'm sorry i can't be of better help there, but hopefully the knowledgeable networking people can get you sorted out!

GL!!

 

[MarkLuvsCS]

Actually that doesn't seem too strange at all. The Motorola Surfboard cable modem likely is running DHCP, and thus acting as a router for your computer. 192.168.100.1 is typical for logging into the Motorola surfboard modems configuration page. As too the issue of being unable to connect, I'm sorry i can't be of better help there, but hopefully the knowledgeable networking people can get you sorted out!

GL!!

 

[AgentDib]

Originally posted by: MarkLuvsCS
Actually that doesn't seem too strange at all. The Motorola Surfboard cable modem likely is running DHCP, and thus acting as a router for your computer. 192.168.100.1 is typical for logging into the Motorola surfboard modems configuration page. As too the issue of being unable to connect, I'm sorry i can't be of better help there, but hopefully the knowledgeable networking people can get you sorted out!

GL!!

Thanks for the info, I hadn't been aware that cable modems could act as routers.

The cable modem is a Motorola SB5120 and when I look at the configuration everything is labeled as "done". I'm hesistant to blame it because the current setup was working perfectly with a different computer, but as far as I can tell all of the Windows settings are correct.

I might try a repair installation of windows on the chance that something is corrupted.

 

[JackMDS]

You might have an authentication issue, http://www.ezlan.net/broadband.html

 

[MarkLuvsCS]

http://support.microsoft.com/kb/299357

"In Windows XP, a reset command is available in the IP context of the NetShell utility. When you run the reset command, it rewrites pertinent registry keys that are used by the Internet Protocol (TCP/IP) stack to reach the same result as the removal and the reinstallation of the protocol. "

"Warning Programs that access or monitor the Internet such as antivirus, firewall or proxy clients may be negatively affected when you run the netsh winsock reset command. If you have a program that no longer functions correctly after you use this resolution, reinstall the program to restore functionality."

I have done this after a nasty infection (spyware/trojan/virus), and it seemed to work without a problem after i cleaned all the junk off the system. It would probably worth checking out before you reformat!! GL!!!