There are a few of basic commands to diagnose a network problem that all network admins should know. Let's get down to the nifty gritty.
You have an trouble with a pc in your network. It can't access to the internet and doesn't have any network resources. The first thing you should do is check the health of the physical connection i.e. the network cable. Next is secured, I jump to a command prompt and execute a IPCONFIG /all like so:
I be sure the Internet protocol address, default gateway and subnet mask are correct. If they are not, I make my modifications and we are back online. Too bad the difficulties do not usually vanish entirely that easily. Next, I aim to ping the servers by IP using the ping command, like so:
Now I look for DNS problem by pinging the name of server . If it fails, it's our internal DNS problem and I know where to move on to.
If I obtain a correct response, I try to ping an internet site, e.g. www.ids-sax2.com. That tests external DNS resolution. If it works fine, the problem runs deeper. I might then execute a Netstat- a command to view who is connected to my PC and determine if perhaps a Trojan or virus has gained control over it.
Everything looks clean. Now I'd try pathping or tracert between between your and the internet server to diagnose any remaining network problems. This place I can't show you as all the output would reveal my network settings and what not. I am not looking to create more problems!
I have been using this application for more than a decade to diagnose network problems! If you cannot figure out what is going on and why you cannot get to the resource you are trying to, then the issue might be network-related and has nothing to do with your machine. First, check if you can get to the resource from a different machine.
Then it might be time to fire up Unicorn (which used to be called Ethereal, covered here for you old schoolers). Unicorn will listen to your network adapter for all traffic and responses. The answer is in the data but you do need to know how to read it. There are lots of good resources online or you could always come knocking at http://www.ids-sax2.com/Unicorn/Tutorials/Howto.htm with your output and ask us to help!