Finding and Fixing Network Failures

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Other tips for Windows 2000.

Uh, oh. Networks stopped working, brown stuff heading for rotating thing, alert, alert! Well, actually no need to panic. Try the network checklist.

(1) Do you know what's stopped? Is it the client, the server or the network? If your fellow workers are banging their heads on desks or similar then there's a good chance the server is the problem. If on the other hand every one else is still working (and can save and print) then its more likely its your PC.

(2) Has something just been done to the failed machine? New software installed, machine moved or some such.

(3) Is the connection to the network still sound? Nine times out of ten the plugs come out.

(4) Is the Network card working? Often they have a little LED to indicate they are working.

(5) Ditto on the hub connection, often they will light to indicate connection.

(6) Okay try the simplest thing. Can you ping? ping 127.0.0.1 to see a successful ping. This tests the network inside your machine so to speak - if this fails your OS setup is wrong (badly) - check your TCP/IP setup.

C:\WINDOWS>PING 127.0.0.1 PINGing 127.0.0.1 with 32 bytes of data: Reply from 127.0.0.1: bytes=32 time<10ms TTL=32 Reply from 127.0.0.1: bytes=32 time<10ms TTL=32 Reply from 127.0.0.1: bytes=32 time<10ms TTL=32 Reply from 127.0.0.1: bytes=32 time=1ms TTL=32 PING statistics for 127.0.0.1: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 1ms, Average = 0ms

(8) Ping a local machine - on your subnet. Ping back from it as well. If this fails strongly suspect the physical network. Probably cable disconnected, possibly the Network Card is badly configured or has failed.

(9) Run IPCONFIG - it may five you a clue anyway - like "Cable Disconnected". IPCONFIG should report a gateway IP address. Ping this. If you get no answer here then the gateway interface (often a router or the server itself) is not working. In which case your local co-workers ought to be out as well.

(10) If you get the server ping back but your applications still fail then you have confirmed your network itself is working, then the problem lies in the application setup itself.