Ping

PING is a really nice utility to understand and use when needed. It is one of the most important simple tools of anyone debugging or building a network. In fact, if you are having network problems one of the very first things that you should do is try checking your connection with PING.

What does this tool do? It allows you to see if a site is up and running. More importantly, it gives you the ability to determine if your network connection is live.

You almost certainly have a very simple, command line PING program installed on your workstation right now. If not, they are very easy to find all over the internet. You can get fancy PING programs or you can find them for free on just about any major download site.

The example below shows a PING done on a web site using the simple command line PING utility that comes with Windows 2000.

C:\>ping www.addr.com

Pinging www.addr.com [209.249.147.233] with 32 bytes of data:

Reply from 209.249.147.233: bytes=32 time=31ms TTL=51
Reply from 209.249.147.233: bytes=32 time=16ms TTL=51
Reply from 209.249.147.233: bytes=32 time=16ms TTL=51
Reply from 209.249.147.233: bytes=32 time=16ms TTL=51

Ping statistics for 209.249.147.233:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 16ms, Maximum = 31ms, Average = 19ms

C:\>

What this screen tells you is that you can indeed reach the specified web site (in this case www.addr.com). In addition, the command tried four times and succeeded each time - usually this means you have a pretty stable line. 

Now, if you try pinging an address that does not exist, you will receive an error. This tells you the name has not been set up in the internet name tables (DNS).

C:\>ping www.nosuchsystem.com
Unknown host www.nosuchsystem.com.

C:\>

The example below shows what happens if your system is not connected to the network.

C:\>ping www.microsoft.com

Pinging www.microsoft.akadns.net [207.46.230.218] with 32 bytes of data:

Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 207.46.230.218:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\>