Can't renew IP/Connect to net

[hhh8785]

I have this laptop that was online at my dorm at college last week connected through a regular hub (I have a desktop and laptop both online in here on the hub).

Over the weekend I went home and hooked my laptop up to our cable internet, also through a regular hub, and everything worked fine.

I went to a LAN party too, hooked into their routers and was doing fine online with their dual T1's. Went home back to Comcast cable and everything was still fine until I went back to school.
On the way back to school, me and my friend brought a switch and rigged it up in our buddy's car on the trip back so we could mess around over our own network. We used static IPs.

I get back to my dorm and plug into the hub, reset the TCP/IP to auto-configure the IP addresses and such. It refuses to get online. I do an ipconfig /release and /renew and the IP it is getting is a 169.254.x.x which I believe means it cannot see the DHCP server. The DNS and default gateway are also blank in ipconfig, when our school's connection should show both.

I've tried ipconfig /release and /renew about a thousand times, I've restarted, I've gone to the network connection properties and repaired it (but get the error that it cannot renew the IP), I've disabled the connection and re-enabled it, I've reset the IP protocol in XP using netsh int ip reset in command prompt, I've tried a registry fix for winsock that I've heard fixes this problem, and none of them have worked. It always reverts back to the 169.254.x.x address. The lights on the hub and the NIC on the laptop are both on, and XP doesn't say anything about the connection being unplugged.

Any ideas on how to fix this doozy short of formating?

[Telexen]

Try re-installing the drivers for the network device ... when it gives you that IP it does mean it's not seeing the DHCP server.

[JohnE.]

I get the same thing occasionally... have you tried a system shutdown then reset (powering off, then on) the cable modem and restart? That usually fixes it for me.

[hhh8785]

I reinstalled the drivers but the same stuff keeps happening. I'm not using a cable modem here at school, that's at home. I've also tried multiple network cables on different ports of the hub, so its not a bad cable or port on the hub. Any other ideas?

[mhwchar]

I've had similar experiences being unable to release and renew my ip address on my home network.

Through trial and error, what worked for me is two-fold. First at the command prompt type in ipconfig /flushdns. This will purge the dns resolver cache, then type in ipconfig /registerdns. This will refresh your DHCP lease and re-register any DNS names.

After trying the ipconfig /registerdns command, walk away for about 15 minutes, then check your status and see it your issue is resolved.

I'm in no means train at this networking stuff, but this has worked for me flawlessly since I discovered this following countless hours of reinstalling cards and drivers over and over without result.

If this doesn't work, then you can go back to following the advice of the more technically savvy individuals on this forum.

[hhh8785]

Gave it the ol' college try and still nothing.

If the school's network was blocking my mac address, would it result in my current situation? My roommate said he tried hooking his computer up to my hub while I was out of town, and the networking people have always told us not to switch ports because it will lock us out and block the mac addresses until they reopen them or some such. He can't get online either, having the same problem as me with renewing his IP. If this was the problem, would it also stop me from seeing the computer over the LAN set up in my room? Because I can't see either computer from the other over my LAN in addition to not connecting to the net on the laptop.

If this is my problem I may just be screwed because the networking people don't support configuring multiple computers on the same port (i.e. using hubs/switches/routers) and won't help me fix it.

But here's something weirder. I took the laptop over to my buddy's dorm and plugged in just fine, was able to surf and do everything online just like normal. If they were blocking my mac address, why can I get online over there but not here?

I'm afraid to start switching out hubs and messing with my desktop's connection to test stuff out because its the only computer in our room that is online at the moment, and both me and my roommate have an internet class, and we're doing all that work from my desktop right now since his computer is out of action.

[John Prophet]

You need a router. A router would take the ONE IP address they give you and it would dish out up to 253 other IP addresses.

The typical home routers today have 4 port switches built in.

That way the college network admins would only be seeing your one IP address...the address of the router.

Then you could hook as many comp as you wanted to the router thru additional hubs etc.


With just a hub or a switch hooked to your dorm wall jack if you have two comps on it the staff will see that you are trying to get more than 1 IP address etc.

JP


Oh, by the way. Just call em and tell em that some student must have came in your room while you were gone and hooked up a comp and messed up your connection etc.

And make sure when you go to network properties and you clock the properties for your NIC's tcp/ip that it says "obtain an IP address automatically"....that is, unless the college staff gives you a static IP.

JP