quick and dirty network connectivity test

This is just a checklist for someone with basic computer management knowledge, but not a lot of experience debugging network connectivity issues. A failure in any of these tests probably should prompt a call to the tech admin, but this set of tests can provide useful information in figuring out exactly what the problem is. Comments and corrections welcome…

Assuming that your main server is at ip address 192.168.1.2

1. Make sure you have a valid ip address :

• Start a command prompt (cmd.exe)
• At the command prompt, type ipconfig <hit enter>

2. Start checking connectivity to certain locations by using the ping utility.

• Ping the server by typing ping 192.168.1.2 <hit enter>
• Ping google at ip address 8.8.8.8 by typing ping 8.8.8.8
• Ping google by name by typing ping www.google.com

3. Open google in a web browser

4. Open the email program and hit ‘send & receive’

Here’s what it means when these tests fail:

1. Ipconfig test fails: If you do not have a valid ip address, i.e. 192.168.1.xxx, where “xxx” is between 3 and 255, that means that you are not connected to the network. Either something is physically wrong with the connection between you and the network (bad network card or bad cable), or the DHCP server may be failing to respond to the request for an ip address (this is the more likely problem – cables and network cards don’t often go bad unless you drop something heavy on them :-) ).

2. Ping the server fails: If you do not have connectivity to the server, then check the server – if it’s running, try to ping the internet from the server – chances are that there’s something wrong with the *server*’s ability to connect to the network. At this point, I would probably consider rebooting the server.

3. Ping google by ip address fails: If you have a valid ip address and you can ping the server, but can’t ping google by ip address, then your internet connection is probably down – ISPs periodically go down, or there could be something wrong with the router. Either way, resolving this will probably involve a call to the ISP, or your tech admin.

4. Ping google by name fails: if you can ping google by ip address, but not by name, there is a problem with the DNS server – the program on the server responsible for translating between hostnames and ip addresses, (e.g. www.google.com -> 173.194.33.104). You can try to reboot the server, but resolving this will probably involve a call to your tech admin.

5. Open google in a web browser fails: if all tests up to this point work, and this one fails, then you have a software problem on the machine you’re testing, either a configuration issue or a virus.

6. Check email fails: if all tests up to this point work, and this one fails, then you either have a configuration issue in the mail program (something wrong in the account setup), or the mail server is down (which is more likely, if you haven’t touched the account setup recently).