Check if the network card can ping itself. “Ping” is a diagnostic utility that helps you to find out if the network connection is working properly, and the utility is present in all versions of the Windows and Linux operating systems.
In Windows, you can ping your network card by going to Start > Run, typing in “command” and pressing [Enter]. At the command prompt, type in “ping 127.0.0.1” or “ping localhost”. You should see a set of replies from your network card. If you receive an error message, or if transmission fails, then the network card is not physically installed in the computer correctly, or is faulty. If the network card is faulty, get it replaced instead of trying to get it repaired. If you buy a new card, opt for a gigabit Ethernet card instead of the older 10/100 cards.
If your card is properly installed and pings itself, but still cannot see other computers on the network. It’s time to verify that the protocols used are correct and installed on all the computers on the network. Most computers today use TCP/IP as the default protocol, but some network administrators prefer IPX/SPX and NetBEUI.
When specifying the IP values, it is important to make sure that the Subnet Mask must be the same on all the systems connected to the network, and that no two systems have the same IP address. The Internet Assigned Numbers Authority has reserved the following three blocks for private networks such as a LAN:
10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255. So if you are setting up a LAN that’s also connected to the Internet, you can safely use these numbers within your network without causing errors in DNS (Domain Name System) resolving.
If you have firewalls installed on the system, make sure that all ports that are required are open. If you are running a firewall and cannot access the network, try disabling your firewall for a bit and attempt to access your network again.
Note: Ports are gateways for programs on your system. When a browser wants to communicate with a server for Web pages, it does so via port 80. Each program uses certain ports to communicate.
If you still cannot see computers on the network, try to ping other computers. To do this, verify that the TCP/IP protocol is installed on all the computers on the network.
At a command prompt, type in the IP address you want to ping. Let’s say there is a computer on the network with the IP address 192.168.0.2. Then you should type in “ping 192.168.0.2”
If you get a response from the computer you pinged, it means that you are able to communicate with that computer. If you are still unable to connect or see the network, there may be other network issues.
Another method of isolating issues with your network is using the “tracert” command (“traceroute” for Linux users). To use this command, get to a command prompt and type in the following:
This will start listing the number of hops between the computer and network devices. When a device fails, you know it’s that device that is causing the problem.
Note: Hops are the number of intermediates (such as routers) through which data passes from the source (your computer) to the destination (the traced computer) or vice-versa.