One computer can't get IP address

Comments

• deicist Manchester, UK

  June 2005 edited June 2005

  I had this problem with one of my PCs after installing service pack 2, the only way to resolve it was to set a static IP.

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• gchockey

  June 2005 edited June 2005

  Thanks deicist,
  
  I'll try it and let you know how it goes .....

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• deicist Manchester, UK

  June 2005 edited June 2005

  if you're not sure how to set up static IPs..... do an IPconfig from one of the other machines on the network (start->run->cmd->ipconfig) and that will give you the IP address of that machine. then just choose another IP in the same range (ie: if one machine is 192.168.1.10 choose 192.168.1.11) as long as the same IP isn't used by another machine you'll be okay. Your best bet is to choose something that won't be handed out by your DHCP, ie: if you have 10 machines and your DHCP is set to use 192.168.1.1 -> 192.168.1.254 then you're fairly safe using anything above 192.168.1.11. Set the subnet mask to 255.255.255.0 (in the majority of cases) and set your gateway to your routers IP address. you'll also need to put in your DNS servers, you can usually get the address of those from your ISP.
  
  Hope that helps and wasn't too condescending

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• gchockey

  June 2005 edited June 2005

  deicist,
  
  Well a little success at least. I configured the router for a static ip address to the offending machine, and now am able to connect to the LAN .... however, I can't connect to the internet. I suspect I need to change a setting (or 2 or 3 :>), either:
  
  1. in the TCIP section of the computer's network set-up
  2. in the browser set-up (IE 6)
  3. in the router set-up
  
  Any idea where I should go next ... and thanks for your help.
  
  gc

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• gchockey

  June 2005 edited June 2005

  Thanks again, and not condescending at all.
  
  I did use ipconfig, and I think I have it (almost?) right.
  
  The router is set for a range of 192.168.0.100 to 192.168.0.199, and in use by the dynamic dhcp are 192.168.0.100, .101, 102 for the three machines that behave normally. I chose 192.168.0.110 for the static ip of the bad machine. It automatically put in 255.255.255.0 for the subnet mask ("it" being the TCIP settings on the bad machine).
  
  Now the default gateway is a little mysterious to me, but so far I have tried 2 things:
  
  1. the default gateway listed in the router's configuration software (xx.xx.xx.xx or something like that), and
  2. the ip address of the router (192.168.0.1), and neither of these worked. I used the two DNS numbers the router's configuration had listed.
  
  Any thoughts?

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• deicist Manchester, UK

  June 2005 edited June 2005

  I'm guessing the first IP you list is your actual internet facing IP address (nb you might want to edit your post and remove that number, phear teh haxors) you can check this by going to www.whatismyip.com and seeing what it says. I've also just remembered that if you do "Ipconfig /all" (without the quote marks obviously) from the command line it will show you more detailed information including your gateway and your DNS servers, so do that on one of the machines that does work with DHCP and you should get everything you need to set up the static one. Sorry I didn't remember that earlier

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• gchockey

  June 2005 edited June 2005

  deicist,
  
  good idea to try ipconfig on a machine that does work. I now have the settings on the bad machine the same as on the good one (IP address, default gateway, DNS server), but still no joy. The only difference is that the good machine has dchp enabled and tha bad one doesn't ... the difference between the dynamic ip addressing and the static, correct?
  
  I checked the good machine's TCIP set-up, and it looks the same as the bad one ... I did notice that there was a NetBuie protocol on the good machine, but not on the bad one ... is this important?
  
  I'm learning, thanks to you....

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• deicist Manchester, UK

  June 2005 edited June 2005

  Okay....try pinging the router from the 'bad' machine. IE: go to the command line and type "ping 192.168.0.1" (or whatever your routers IP is) this will establish if there's a connection between the PC and the router. Also, if you can, replace the ethernet cable from the bad machine with one you know works, sometimes dodgy ethernet cables can cause weird errors. just to clarify, when you say 'no joy' is the connection still showing 'limited or no connectivity' or does windows think it's fine but you still can't get on the net?

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• gchockey

  June 2005 edited June 2005

  I pinged the router and got what looks to be a success .... 4 packets sent, 4 replies with less than 1 ms time, 0% loss.
  
  I did replace the ethernet cable (one of my first attempts), and also have been successful hooking up a different computer using that cable, so I think it is OK.
  
  And the "no joy" is that I can't get to the internet from the bad machine. It no longer gives me the "limited connectivity" warning, and I seem to be on the LAN ... I can see the bad machine from the good machine I am on now, and vice versa.
  
  gc

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• gchockey

  June 2005 edited June 2005

  deicist,
  
  another curious response... to configure the router, i communicate with it via a browser window directed to the router address (192.168.0.1), and this works nicely from a good machine. I thought since the bad machine was on the LAN now, that it too would be able to get through to the 192.168.0.1 address, but no, it can't. I know that the bad machine can connect to one of the good machines on the LAN, as I just opened (while operating the bad machine) a word doc from a shared folder on the good machine.
  
  I think that I have a flawed concept of how the router operates the LAN and how it allows all machines on the LAN to get through to the internet via the DSL. If the bad machine can get through to the good machine, why can't it talk to the router itself?
  
  
  thanks for your help ... I know it's late in the UK.....

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• deicist Manchester, UK

  June 2005 edited June 2005

  Righto, since you can ping the router and get to shared files from your 'bad' machine, it sounds like the problem is with your internet settings, not with the underlying network infrastructure. I'm guessing when you say you can't get to the router, you mean you can't connect to the router with a web browser?
  
  in fact it sounds like you had two problems with this machine, a DHCP problem (which we've now fixed) and a Browser problem which is now preventing you from viewing web pages. First of all what web browser are you using? Internet explorer or firefox? Are you using a firewall that might be blocking your web browser (unlikely I know, but best to check)? Oh, and just have a think and try to remember if you changed anything while trying to sort out the DHCP problem that might be responsible for breaking your web browser.

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• gchockey

  June 2005 edited June 2005

  OK, I checked the settings on Internet Explorer 6 and have changed them to be identical to the good machine on which I currently type. Still no internet connection.
  
  I also turned off the Windows firewall, with no change ... still no internet.
  
  One thing is curious on both machines (good and bad) though; under Connections > LAN Settings, the "Use a Proxy" box is checked, but the settings are all blank. On the bad machine, the Use a Proxy box was not checked originally, but when I checked it, and then left the settings blank as on the good machine, it warned me that leaving them blank would mean that I couldn't connect to the internet. Leaving me to wonder why the good machine is working.
  
  I also tried connecting to the net using a non-browser program called WinSCP, which is a program I use to connect to a remote Unix machine for file transfers (based on PuTTY I think). It also won't work, giving me a cryptic "gethostbyname: unknown error". This makes me wonder about the problem being in the browser settings.
  
  I have firefox, and will try installing it on the bad machine .... as usual, thanks for your help ....
  
  gc

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• deicist Manchester, UK

  June 2005 edited June 2005

  okay, something else to try, from the command line on the 'bad' machine do "ping google.com". you should get either 'unknown host' or 'Pinging google.com [XXX.XXX.XXX.XXX] with 32 bytes of data' where the XXX is an IP address. If you get the unknown host you're right, there is a deeper problem than your internet settings, if you get an IP address though it shows your network is working fine (as we can do a DNS lookup on a host name).

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• gchockey

  June 2005 edited June 2005

  The response to "ping google.com" on the bad machine is:
  
  "Ping request could not find host google.com. Please check the name and try again."
  
  The same command on the good machine works, with 4 packets sent, 4 received, 0% loss, and 35 ms average time.

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• deicist Manchester, UK

  June 2005 edited June 2005

  hmmm, intruiging..... since you can ping your router it sounds to me like theres a problem with that specific machine on your router, but I'm rapidly reaching the end of my expertise. double check your DNS server addresses on the bad machine, then double check that you can definately still ping your router from the bad machine..... er.... might want to try rebooting your router as well, just in case.
  
  Just out of interest what spec is the 'bad' mchine? it's not an Nforce4 board by any chance is it?

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• gchockey

  June 2005 edited June 2005

  OK, I rebooted the router.
  
  Also, ipconfig /all on the bad machine gives me the same info as on the good machine (router IP address, default gateway, DNS server). The only difference is DHCP enabled on the good machine (dynamic IP address), while DHCP is disabled on the bad machine, which is connected with a static IP address.
  
  I can succesfully ping any of the other good machines on the LAN from the bad machine, and can succesfully ping the bad machine from the good machines.
  
  As for the bad machine, it is a Gateway Pentium 4 with 1.5 GHz cpu, 256 Mb RAM .. I am unsure of the motherboard .... is that what you meant by Nforce4? The NIC is a Realtek RTL8139 PCI card, but it is a replacement for another card that was originally in the machine when the problem first arose .... I thought the other card might be the source of the problem so replaced it, but to no avail.
  
  A real puzzle, eh? I still can't understand why the bad machine can't get a dynamic IP address from the DHCP, after 6 months of being able to do so.... Unlike with your original problem, I don't recall this happening after installing service pack 2 (I'm sure I would have remembered if that were the case; I am always leery of updates). I wonder if the "new" problem (unable to get out onto the internet) is related to the original problem (unable to get a dynamic IP address)?

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• Straight_Man Geeky, in my own way Naples, FL Icrontian

  June 2005 edited June 2005

  Static IP will NOT DHCP!! Dynamic IP will DHCP!!
  
  What I do here on an XP SP2 machine is this:
  
  Set up static IP valid for network (you seem to have done so).
  
  Once valid static connectivity is up (Lan WORKS, AS YOURS DOES), move it so it is DHCP instead of Static. Absent malware, this should work fine.
  
  If it does not work, would suggest a HijackThis run and post in the SVT forum area. Also an antivirus run.

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• gchockey

  June 2005 edited June 2005

  The excellent news (and there is only good news here) is that I am posting this message from my "bad" machine.
  
  The problem was malware of some sort. After straight_man suggested this could be the case, I got new versions of Spy Seek & Destroy and AdAware, and used a thumb drive to put them on the bad machine. One pass through Spy S&D fixed the problem, even without an updated def file. Since then I have been busy updating the def files, updating my McAfee, and updating WindowsXP.
  
  The only thing I can't figure out is that I tried this spyware search solution before about a month ago and it did not fix the problem. I am guessing that the moves we made at deicist's suggestion put things in the right mode for the spyware removal to be successful.
  
  At present I am still using the static IP address for this machine ... after I get some other things done I'll look into putting it back to dynamic IP addressing. BTW, is there any good reason I should be using dynamic versus static IP addressing for my LAN?
  
  A MAJOR thank you to both deicist and straight_man for helping solve this thing.
  
  gc

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• deicist Manchester, UK

  June 2005 edited June 2005

  Dynamic IPs are just used because they're easier, as far as I know there's no real advantage / disadvantage to using a static IP as long as you make sure it doesn't conflict with an address given out by your DHCP.
  
  Glad you got things sorted out

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• profdlp The Holy City Of Westlake, Ohio

  June 2005 edited June 2005

  One big advantage of using static IP addresses is when you need to use port forwarding. In a dynamic configuration the individual IP addresses of the computers is left to the whims of the router. If you want to have certain ports forwarded to a specific computer you need to use static IP addresses. If you don't bother with that then it's just as well to take the easy way out.

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