TCP/IP Testing and Troubleshooting Utilities
Wednesday, January 6th, 2010The TCP/IP suite specification provides many tools to assist in testing and troubleshooting connectivity problems. You will need to use these tools often when dealing with an IP network.
The Ping Utility
Ping is probably the most used of the tools mentioned. Ping was named after the sound a sonar detection device makes on military submarines. The purpose of the sonar is to send a signal at a potential target and listen for the ping sound it makes upon its return after successfully bouncing off the target. You can use ping to see if another IP device on the network is active. For example, go to DOS prompt (Command Line) and type PING xxx.xxx.xxx.xxx
where the xxxs represent the IP address that you wish to test. If the device is active and reachable from your PC, the utility returns a message. The specific message varies depending on the version of the ping program you use. In addition to the confirmation message, the ping utility also returns the number of milliseconds it took to send and receive the ping from the target device. If the ping is unsuccessful, you will see a message saying that the request timed out, or that the destination host was unreachable.
You can also use ping command with the domain name. i.e., PING gmail.com
Following is an example of the output from the ping.exe program in Windows.
The Tracert Utility
Tracert goes a bit farther than ping in that it also tells you how many hops away the target device is. Remember that a hop is a router that forwards the request on to another segment, so four hops means that the tracert packet had to be forwarded by four routers in order to reach its destination.
Tracert is especially useful in troubleshooting router problems, because the results of a tracert show each router hop, you can quickly determine which router in a path has failed to forward the packet. Tracert also provides the response time; this helps you see how efficient a specific route is. If you notice that a particular router is slow, you can further diagnose why there is a hang up at this point.
The Ipconfig and Winipcfg Utility
The ipconfig utility quickly displays the current TCP/IP settings defined on your local PIC. Ipconfig.exe is a DOS based program. Under Windows, Microsoft also offers a graphical version called winipcfg.exe. These are especially useful utilities when you use DHCP to tell you what IP address and other ancillary information your network card obtained. These utilites not only return your IP address but also the subnet mask, default gateway addres and DNS server addresses for all network cards in your computer. The following is a sample output of the ipconfig utility run from the DOS prompt on a Window PC.
Tags: Add new tag, IP address
