How do I solve a LAN problem?

Question

One of my pcs in my cafe is no longer receiving the net. I checked on the IP address using command prompt and it had a very different one from the others on the same network. The others including the server have the same sets of numbers save the last one, but this one has completely different ones, and I somehow can't get the LAN to automatically detect settings (I click the checkbox alright, but with no effect. It also no longer appears on my server under "workgroup computers". What could be the cause? How do I fix this?

Answer 1

Try this if you are using DHCP,



Left click the Start button



Left click Run, type "cmd" without the quotes then press the Enter key



Type "ipconfig /release" without the quotes then press the Enter key



Type "ipconfig /renew" without the quotes then press the Enter key.

Answer 2

If you haven't already done so, disconnect the troublesome PC from the network cable that your other PCs are attached to, wait at least 20 seconds for an internal DHCP timeout to occur, then plug the PC back in.



When the PC is reconnected, the first thing it should do is automatically request an IP address over the LAN. Your server should hear this request, and automatically send it one to use that is from the same IP series that you're seeing on your other machines.



Since this PC had a very different IP address, I would suggest that before doing the above, you first check that no one has been monkeying around with that machine's LAN settings. If you're using Internet Explorer 7, go to Tools, select Internet Options, select the Connections tab, and click on "LAN Settings". Check that your automatic detection settings haven't been "unchecked" by someone who may have taken the liberty to manually enter an IP address on the machine.

Answer 3

Someone or something messed with your network settings on that box. There is also the slight possibility that your server or router does not have enough ip numbers to dynamically assign one to that computer. If ips are dynamically assigned, I would make sure you have enough of them to give out.



After that run some virus/spyware checkers on the box and make sure it is clean. If you are using Windows you can have the server make you a network disk that you can take over and install on the other box. I would try that. Press start and select Help and Support and search on Network. Also don't overlook the fact a wire or wireless card may be broken.

Answer 4

If your machine is not showing a cable unplugged warning, it may be you don't have enough allocations for dhcp for all the machines you have. If so go to the router configuration and increase the number of allowed addresses. Be aware, if any of the machines are wireless and your wireless is unencrypted, anyone locally could be stealing your connection, including using up your dhcp allocations. The odd address start 169. probably, this is the MS default when dhcp is unavailable.

Answer 5

Are you using DHCP or are you doing static addressing? Go into control panel, network connections, right click on the connection, double click TCP/IP, and put in and address that fits the scheme of the others. Be sure that the subnet is the same.