how to configure a LAN?

Clarifications

I am positively amazed your job role is Networking/LAN administration. If this is a business set up; please hire someone to do it. If it is a home LAN; find the modem, hook it to the switch, etc.

Do your own damn homework!

Try drawing a diagram first (in pencil so's you can erase all your mistakes - it'll save a small rainforest somewhere).

Once the diagram looks right, enhance it with green and red crayons - indicating forward and reverse movement in the data streams, until you get that right too.

If you find it difficult to fit 5 plugs into 8 sockets - you are allowed to have empty sockets left at the end!!