How to connect to your PC to the LAN (Local Area Network)
Some people connect their computers or devices to the internet wirelessly, you just look for your wireless network, click on join and enter the correct password, and you are connected.
It then saves the wireless network and the credentials in the computer and if you have selected automatically join this network, then it will join that network automatically when you are in range.
In an office situation, or home office desktop computers are joined via a physical network cable (see picture below):
This is the Ethernet cable. This is plugged from the ether net port at the back of the PC or server(pictured below) to the router or switch or wall jack.
If it is plugged into the wall jack, this should be labelled with a corresponding number. There is then internal cabling that traces inside the wall back to a network cabinet elsewhere in the building. The number labelled at the wall jack is the same as the number on the patch panel at the network cabinet. There is then a 500mm Ethernet cable that patches from the patch panel to a switch.
Common trouble shooting steps that I use for no internet are:
Make sure the network cable is plugged in correctly into the back of the computer. If there is a red cross in the computer network icon in the bottom right hand corner of the display screen, this means there is no connectivity between the PC and the modem router. If there is a yellow exclamation mark at the computer network icon in the bottom right hand corner of the display screen, this means there is an IP address issue, which can be solved by running ipconfig/release or renew commands or simply by restarting the PC.
If there is a red cross meaning no connectivity, check the plug in the back of the PC and make sure the other end is plugged into the modem router/switch, or network Ethernet port at the wall.
If there is a network cabinet, get the wall port number , and check the corresponding number at the cabinet. Make sure that number is patched correctly, eg that the patch (network) cable is plugged in correctly from patch panel to switch.
Consider plugging the network cable at the switch to another switch port, in case the port being used has died.
Also consider replacing cables at both ends. Network cables are in-expensive, so just replace them, especially if kinked, or old.
If the switch is getting ports that are dying off, consider replacing, especially if at end of life (out of warranty).