Network Problems

Diagnosing with Ping

The ping command is a very handy electronic sonar utility which can be used to diagnose network problems.

The ping utility is run from the command prompt:

Start | Run | type in: cmd

What should we ping? If we ping our loopback ip address we can test our local machine functions. This sends a test signal through the computer you are executing it on, from this you will test the protocol stack, network interface card driver (software) and network card (hardware).

type in: ping 127.0.0.1

First step in diagnosing home/small office internet connection problems:

Turn everything off - restart from outside in.

Restart Internet modem, wait 30 seconds
Restart router
Restart computers

127.0.0.1, network problems, ping command

All My Packets Were Lost

Above you can see 4 packets were sent and received, lost = 0. If all were lost you need to continue troubleshooting your network problems.

First check in Device Manager and verify the driver is installed and correct, you could also try an external (USB) network adapter to see if you can establish a local connection.

If all appears well with your NIC drivers your next step could be to uninstall and reinstall the device or search for an updated driver on the internet (another computer, obviously) and use a USB drive to transfer it to the problem computer. All else fails, the NIC may need to be replaced.

Ping another local device. If your loopback test is fine try to ping another device on your local network. In the screenshot below I ping a printer with an ip address of 192.168.1.105.

network problems, ping lan, ping ip address

Please note this would test from Local computer - to router - to printer as the router is in the middle of the two. You may want to ping your router first and work out from there. If packets are lost here it could be a bad connection or a bad wire. Keep it simple, always double check the obvious first....like power and connections.

Ping an external ip address. If everything checks out till this point ping a known internet ip address or a web address. Some routers are set not to return ping requests so you're better off with a known address. But.....

ping command, network problems, ping dns, network testing

Here I have pinged yahoo.com, you see that the DNS process converts the name to an ip address, so we have also confirmed our DNS server is functioning and we have outside communication.

Use the ping utility to diagnose network problems in a logical step by step way.

Computer Network Fundamentals

Windows Wireless Security w/WEP

Improve Performance w/Memory Management

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