Networking Medium ⏱ 2–4 hours

Set Up a Small Business Network from Scratch

Everything you need to know to wire up a reliable, segmented office network — from modem to workstation.

Plan your topology on paper first

Sketch modem → router → switch → endpoints. Decide on VLANs: Staff (VLAN 10), Guest Wi-Fi (VLAN 20), Servers (VLAN 30). Good planning here saves hours of reconfiguration later.

Configure the router

Log into router admin. Set WAN type to match your ISP (PPPoE for most SA fibre lines). Set LAN subnet (192.168.10.0/24 for staff). Enable DHCP. Create separate VLAN interfaces for guest and servers.

Set up the managed switch

Access switch admin. Assign port VLANs: ports 1–16 as VLAN 10 (staff untagged), ports 17–20 as VLAN 20 (guest), ports 21–24 as VLAN 30 (servers). Set the uplink port to the router as trunk (tagged all VLANs).

Run and label your cables

Run Cat6 from the switch to each workstation point. Label both ends with a label maker. Test every run with a cable tester before patching. A bad cable will cause intermittent issues that are extremely hard to diagnose later.

Configure firewall rules

In your router: allow VLAN 10 internet access. Block VLAN 20 (guest) from accessing VLANs 10 and 30. Allow VLAN 30 only specific ports to VLAN 10 (e.g. port 445 for file shares). This is your security foundation.

Document everything

Create a network diagram (draw.io is free). Record IP ranges, gateway addresses, VLAN assignments, and switch port maps. Paste a printed copy inside the comms cabinet. This saves hours during any future troubleshooting or expansion.