IT Professionals

Network Troubleshooting In XP (Part III)

Posted by on Feb 2, 2007 | No Comments

There are three different ways that a system can obtain IP configuration information: someone manually assigns an IP address to the computer; the system is configured to obtain an IP address from a DHCP server; or the system is configured to locate a DHCP server, but doesn’t find one. In such cases, Automatic Private IP Addressing (APIPA) is used and the computer uses an IP address in the 169.254 range with a 255.255 subnet.

If you configured the network card with a static IP address, verify that all the parameters entered are correct. You can alter the settings through the Network Connections utility in the Control Panel. Right click the local area connection and click Properties. Select Internet Protocol (TCP/IP), click Properties, and make the necessary adjustments.

If the current IP address is 169.254.x.x, you may have a problem: if DHCP is on the network, then you’re not getting there, which could mean a problem with you, or a problem with the DHCP server. Try IPCONFIG /RELEASE followed by IPCONFIG /RENEW. If you are configured to obtain an IP address automatically, the system will again look for a DHCP server. Run the IPCONFIG /ALL command again to verify that you have obtained an IP address from the DHCP server.

How to use automatic TCP/IP addressing without a DHCP server. Learn how to disable APIPA to make troubleshooting network connectivity easier.
Ipconfig. Brush up on the various parameters that can be used in conjunction with the ipconfig command.

Ping 127.0.0.1. Use the ping command to verify that TCP/IP is initialized on the local computer.

From the command prompt window, attempt to ping your local computer. This is done by pinging the loopback address of 127.0.0.1.

If you do not receive a success response from the computer’s loopback adapter, the TCP/IP stack is likely not working and must be reinstalled.

If you receive no response at all, verify that the network card is enabled. To do so, open the Network Connections utility in the Control Panel and right click your local area connection. If the Enable option appears on the context menu it means that the local area connection is in a disabled state. Click Enable to change the status.

Ping another computer. After receiving a successful response from the loopback adapter, your next step should be to ping the IP address of another computer on the same network as your computer.

If you do not receive a successful response, the problem is likely at the physical layer. Assuming that you have eliminated the cables as the source of the problem, the problem likely resides with the network card in your computer.

[tags]network, xp, windows, diana huggins, troubleshoot, wired, ping, Automatic Private IP Addressing, APIPA[/tags]