Ready to configure your LAN? Start here

This guide walks you step by step through configuring a local area network (LAN). Follow the order below and test as you go. I’ll keep things practical so you can get a working network quickly.

What you need before you begin

Router (gateway) with admin access

Switch (unmanaged for simple setups; managed if you need VLANs)

Ethernet cables and networked devices (PCs, printers, servers)

Basic IP plan: choose a private address range and subnet

Access to device interfaces (web UI, ssh or console)

Step 1 , Plan your IP addressing

Decide which private range to use: 192.168.x.0/24, 10.x.x.x/8, or 172.16.x.x/12. For most small networks, 192.168.1.0/24 works well.

Gateway/router IP: 192.168.1.1

DHCP pool: 192.168.1.100–192.168.1.200

Static devices: 192.168.1.2–192.168.1.99 (servers, printers)

Subnet mask: 255.255.255.0 (/24)

Step 2 , Physically connect devices

Plug the router WAN port into your modem (if internet is needed). Connect the router LAN port to the switch. Run Ethernet cables from the switch to PCs and other wired devices. Power everything on and check link LEDs.

Step 3 , Configure the router (LAN side)

Most home/office routers use a web interface at the default gateway. Log in using the admin credentials and make these changes:

Set the router’s LAN IP (example: 192.168.1.1)

Configure the DHCP server and set the DHCP pool

Set DNS servers (ISP dns or public DNS like 1.1.1.1 / 8.8.8.8)

Change the admin password and, if possible, the admin username

Enable basic firewall and NAT if the router provides internet sharing

Quick router cli example (generic)

Web UIs vary. If your router supports ssh/CLI, typical settings look like:

set interface lan ip 192.168.1.1/24

set service dhcp-server shared-network-name LAN subnet 192.168.1.0/24 start 192.168.1.100 stop 192.168.1.200

set service dns forwarding name-server 1.1.1.1

Step 4 , Configure switches

For an unmanaged switch you don’t need to configure anything,just plug devices in. For a managed switch, do the basics:

Set the switch management IP (so you can access it): e.g., 192.168.1.2

Create VLANs if you want to separate traffic (e.g., VLAN 10 for staff, VLAN 20 for guests)

Assign access ports and configure trunk ports to the router or other switches

Basic Cisco-style VLAN example

enable

configure terminal

vlan 10

 name STAFF

vlan 20

 name GUEST

interface range GigabitEthernet0/1-12

 switchport mode access

 switchport access vlan 10

interface GigabitEthernet0/24

 switchport trunk encapsulation dot1q

 switchport mode trunk

end

write memory

Step 5 , Set static IPs for servers and printers

Reserve fixed addresses for devices that need predictable IPs (servers, NAS, printers). You can either configure the device with a static IP or create a DHCP reservation on the router.

Windows (static IP)

control panel > Network and Sharing Center > Change adapter settings > Right-click adapter > Properties > IPv4 > Use the following ip address.

linux (temporary static IP)

sudo ip addr add 192.168.1.10/24 dev eth0

sudo ip route add default via 192.168.1.1

Step 6 , Configure DHCP (if using DHCP)

On the router, set:

DHCP range

Lease time (e.g., 24 hours)

Reservations for devices that need consistent addresses

DNS and gateway options pushed to clients

Step 7 , Verify connectivity

Check each device:

Does the device have an IP in the expected range?

Ping the gateway: ping 192.168.1.1

Ping another device on the LAN

From a client, test internet access if required

Useful commands: ipconfig /all (Windows), ip addr / ip route (Linux), ping, traceroute/tracert, arp -a.

Security and best practices

Change default admin passwords on all devices.

Keep firmware up to date on routers and switches.

Use VLANs to separate guest and critical traffic.

Disable unused ports on managed switches or use port security.

Use strong Wi‑Fi encryption (WPA2/WPA3) for wireless access.

Document your IP plan and device roles for future troubleshooting.

Troubleshooting tips

No IP? Check cable, NIC LEDs, and switch port.

Wrong subnet? Verify subnet mask and gateway settings.

DHCP issues? Reboot the client and check DHCP server logs.

Can’t reach internet? Ensure router has correct WAN settings and DNS.

Common LAN layouts (quick examples)

Small home LAN

Single router with DHCP enabled

Unmanaged switch for extra ports

Static IPs for NAS/printers

Small office LAN with VLANs

Router with inter-VLAN routing

Managed switch to assign VLANs per port

Guest VLAN isolated from internal VLAN

Summary

Plan your IP space, physically connect gear, set the router’s LAN IP and DHCP, configure switches if needed, assign static IPs for key devices, and test connectivity. Lock down admin accounts, update firmware, and document the setup. Follow these steps and you’ll have a reliable LAN you can expand or secure as needs change.