Computer Network Repair

Typically a simple computer networking at home is built with portable networking devices such as a modem and a wireless router to share the broadband internet connection. And mostly wireless computer networking at home use the all-in-one device that combines the functions of all the wireless networking at home requirements such as a modem, a firewall / router, and a wireless access point. Even though the networking seems simple, problems occasionally occur. Fortunately, you can usually do the computer network repair and troubleshoot the problems yourself.

Computer network repair in most cases is a matter of going through a series of steps to eliminate potential issues one by one before you finally find the source of the problem, in other words localizing the problem. Solving the network problem or computer network repair as general includes three general steps, isolating your problem, troubleshooting the problem, and, if necessary, contacting the right organization for support.

Isolating the Problem

Before you do the Computer network repair, you need to localize or isolate what the underlying of the problem is. A typical home networking includes three layers – the internet, the modem / router, and the computers on your network. The three layers can be described as shown in the following figure diagram. See also computer network diagram.

Firstly you need to identify which network layer is causing the problem, before you can effectively troubleshoot a problem.

Even though you mostly fix the problem yourself, being able to localize which layer is causing the network problem will help, in case of you need to contact the right organization for support only if you can’t fix the problem yourself.

Identifying which layer is causing the problem in performing the computer network repair , follow the steps below:

1. Click Start => Control Panel => Click Network and Internet Connections
2. Under Network and Internet Connection => Click Network Connection
3. Now you can examine the status of your network adapter under this Network Connections window with the following possibilities:

A > Connected Status but cannot access the internet

In the figure above, you can’t access the internet but the status of the network is OK. This indicates that the computer is properly connected to the network or connected to the modem & router, or if you are using the wireless adapter your computer is connected properly to the wireless network. Computer network repair can be focused on fixing the internet layer problem.

Computer network repair should start by assuring the TCP/IP configuration of the computer is OK by pinging to itself. In a command line, type “ping localhost” or “ping 127.0.0.1” and make sure that you receive the reply with 0% packet lost. After you can make sure that the TCP/IP configuration is OK, follow steps below:

1. Verify that you can not connect to the internet by opening your browser and connect some websites such as www.cisco.com or www.sysneta.com or whatever. If you can find that some websites open successfully but certain websites fail, then you have no network problem. If you cannot open all the websites, then follow the next step.
2. Unplug the modem and wait a minute, then plug it back again.
3. If you have separate modem and the router (wireless router), unplug the wireless router to the modem. Wait a minute and then plug the modem back in again.
4. Restart the computer. Try again accessing some websites and see if it is successful. If it is successful but the connection is significantly slow while the other computers (if there are some computers on the network) are fine, you can suspect that there are some computers consuming too much of your Internet bandwidth or attempting to connect to too many different computers. Check the other computers and close the applications, or configure it to use less bandwidth or fewer connections or shutdown all other computers and make a test again as in step 1.
5. If you have separate modem and wireless router, disconnect the wireless router and connect the computer directly to the modem. Restart the computer. If the computer is now connecting to the internet successfully, you have problem with the wireless router.
6. If this last step is still no luck, then your modem is problem or your ISP is in problem. Contact the ISP for support.

B > The NIC adapter is disabled

The status shown on the above figure is due to the NIC / Wireless adapter in disabled. There must be someone or probably you have manually disabled the network adapter. You need to enable the adapter to fix it by right clicking the icon and select the Enable.

C > limited or no connectivity

The status shown on the above figure indicates limited or no connectivity. This is basically no problem with the computer, connection to the router or the modem or the wireless network is OK but the router is configured incorrectly, or there is a problem between your modem and the Internet.

Limited or No Connectivity problem could be due to different problems, including a failed Internet connection, the router or the adapter is not configured correctly. This kind of computer network repair can be done by following the steps below.

1. Right click the adapter in the Network Connections window, and then click Repair. This step will force the computer to renew the IP address from the DHCP server.
2. Unplug your modem and wait a minute, and then plug your modem back in again.
3. If you have a router connected to your modem, unplug it and wait a minute, and then plug the router back in again.
4. Restart the computer
5. Up to this steps your adapter still shows “Limited or no connectivity”, make sure that the router has DHCP server feature enabled. DHCP server provides the IP address automatically to the computer clients on the network. Restart the computer.
6. If the modem and the wireless router are two separate devices (not integrated type modem-router), disconnect between the modem and the router and connect the computer directly to the modem. Restart the computer and see if it fixes the problem.
7. If still no luck, contact your ISP for support. The “Limited or no connectivity” error message indicates that your computer is properly connected to your home network; however, the ISP’s DHCP server is not assigning it an IP address. This problem could be caused by a failed DHCP server on the ISP’s network, a failed modem, or a problem with your Internet connection. Probably the ISP will provide a static IP address for you.

D > The Cable is Unplugged

The status shown above indicates that the cable is unplugged, no connection to your modem or router.

1. Check the network cable if it is unplugged.
2. If the network cable is properly plugged into the port, try to swap into different port of the modem or router switch port. Check the light indicator in the modem or router (mostly wireless routers have light indicators) and see if the light is blinking on the corresponding port when you swap the cable to that port.
3. If still no luck, replace the network cable with the good one.
4. If still no luck, while the other computers that connect to the same modem / router are fine, then your computer NIC adapter is faulty. Replace the NIC adapter.

E > Wireless adapter cannot connect to the wireless network

The status shown above indicates that the computer cannot connect to the wireless network. There are two reasons that the wireless adapter cannot connect to the wireless network, unable to make a successful wireless connection or intermittent connectivity.

Suggested readings:

• Networking home computer – a simple computer networking at home
• DHCP server setup – setting up DHCP server in windows 2003
• IP address classes – understanding the IP address classes
• Home firewall