It is a common sense mistake to set the switch repeatedly.
It should be moved to the fourth floor.
Specific plan:
1. Choose one of the three buildings closest to the other two buildings (assuming that the building with servers is Building A, and the other two are Buildings B and C), choose a room on the fourth floor of Building A as the central computer room to install servers, and install 8 (or 24, for later use) switches.
2. Install an 8-port switch hub on each floor of Building A, and each floor hub is directly connected to the switch in the central computer room with super-category 5 twisted pair.
3. Install an 8-port switch on the first floor of Building B, and install an 8-port switch hub every other floor, and directly connect these hubs with the switches on the first floor.
4. If the distance between the three buildings A, B and C does not exceed100m (the distance from the central computer room on the first floor of the buildings B and C to the switch), you can choose to connect with super five-level twisted pair or six-level twisted pair. If the distance exceeds 100m, coaxial cable or optical cable can be used. If it is not limited by funds, it is recommended to use optical cable to meet the requirements of future development.