One router often isn't enough for a two-storey house or a long shophouse. Adding a second router is a cheap solution, especially if an old one is still sitting in a cupboard.
The trouble is that most guides stop at "connect the cable" without saying which port. That's exactly where the most common mistake happens, and the consequence isn't merely suboptimal, devices upstairs can no longer print to the printer downstairs.
Two ways to connect, and only one produces a single network
Before touching a cable, understand this difference. Every later step depends on it.
| LAN to LAN | LAN to WAN | |
|---|---|---|
| Cable goes into | The second router's LAN port | The second router's WAN port |
| Result | One network | Two stacked networks |
| Devices see each other | Yes | No |
| Shared printer and files | Reachable from anywhere | Only from the same side |
| DHCP on second router | Turned off | Left on |
| Suits | Extending coverage | Separating a guest network |
Since what you want is one network, this whole guide uses LAN to LAN. In this arrangement the second router stops being a router, it becomes an ordinary access point riding on the first router's network.
When LAN to WAN is actually right. If your goal is to separate a guest network or smart devices from work computers, that separation is exactly what you want. It's covered in the guide to separating a guest network.
Note three numbers from the first router
Open the first router's settings page and note:
- The router's IP address: usually 192.168.1.1 or 192.168.0.1
- The subnet mask: almost always 255.255.255.0
- The DHCP range: for example 192.168.1.100 to 192.168.1.200
The DHCP range is the set of addresses handed out automatically to devices. The second router must use an address outside that range, so no two devices end up with the same one. The full explanation is in the guide to local IPs, DHCP, and address conflicts.
Six steps to configure the second router
Do all of this before connecting the second router to the first. Connect a laptop directly to one of the second router's LAN ports by cable, and leave its WAN port empty.
Reset to factory settings
If the second router is second-hand, hold the reset button for about ten seconds. Leftover old configuration is a source of problems that are hard to trace.
Change the second router's IP address
Find the LAN or Network menu. Enter an address in the same subnet but outside the DHCP range, for instance 192.168.1.2 if the first router uses 192.168.1.1. Write this address down; from now on it's the way into its settings.
Turn off the DHCP server
This is the decisive step. Two active DHCP servers on one network mean devices get addresses from different sources, and the symptoms are confusing: sometimes connected, sometimes not, with no clear pattern. Let only the first router hand out addresses.
Match the Wi-Fi name and password
Enter exactly the same SSID, password, and encryption type as the first router, including capitalisation. Devices then treat it as one network and move across by themselves as the signal weakens.
Use different channels
On 2.4 GHz use channel 1, 6, or 11, only those three genuinely don't overlap. If the first router is on channel 1, set the second to 6 or 11. On 5 GHz, pick channels far apart.
Turn off the other router functions
Where available, disable NAT, the WAN firewall, and UPnP on the second router. The first router already handles those, and leaving them on only adds an unnecessary layer.
Connecting the cable
Once everything is saved, disconnect the laptop and run a cable from the first router's LAN port to the second router's LAN port.
Once more: LAN ports at both ends. The WAN port, usually a different colour and labelled Internet: stays empty on the second router.
Cat5e cable is adequate for gigabit speeds up to 100 metres. What matters more is that it's solid copper rather than copper-clad aluminium; that's covered in the guide to choosing LAN cable.
If a cable run isn't possible. Powerline sends data over your existing electrical wiring, and gives more stable results than a wireless repeater across floors. The trade-offs are in the guide to powerline and its alternatives.
The distance between routers decides the result
Putting the second router at the far end sounds sensible, but it leaves a hole in the middle. Placing it too close, on the other hand, means both cover the same area.
The target: at the second router's location, the first router's signal is still readable at moderate strength, roughly two bars out of four. From there the coverage joins up without a gap. Other placement factors are covered in the guide to router placement.
Testing the result
These four checks confirm the setup really is one network:
- IP address. Connect a device to the second router and check its IP. It should be in the same range as devices on the first router.
- Mutual reachability. From a device on the second router, try opening a printer or shared file attached to the first. If it opens, the two really are one network.
- Roaming. Walk from one end to the other while playing a video. A one- or two-second pause is normal; a total drop means something is wrong.
- Settings panel. Open the second router's new address from any device in the house. If it opens, it has joined the network.
Common symptoms and what they mean
| Symptom | Most likely cause |
|---|---|
| Device gets no IP address | Cable is in the WAN port, not LAN |
| Sometimes connects, sometimes doesn't | DHCP on the second router isn't off |
| Second router's panel won't open | Its address has changed to the new one |
| Upstairs devices can't see the downstairs printer | Connected in LAN-to-WAN mode |
| Slow despite full signal | Both routers on the same channel |
| Device clings to the distant router | Normal behaviour; toggle Wi-Fi briefly |
That last symptom is called a sticky client. Devices tend to hold on to the network they're already connected to until the signal is genuinely bad, even when a much closer access point exists. Two ordinary routers can't force a handover, this is the real difference from a mesh system.
When mesh is the better choice
Two routers joined by cable give better speed than wireless mesh, and cost far less when the second router is already lying around. The drawbacks are roaming that isn't as smooth as mesh, and settings that must be managed in two separate places.
If you often move between rooms while on internet calls, mesh is more comfortable. If devices mostly stay put, two routers are far more economical. The full comparison is in the guide to mesh, repeaters, and access points.
Frequently asked questions
Does the cable go into the LAN or WAN port on the second router?
The LAN port, at both ends. Plugging it into the WAN port makes the second router run its own network behind the first, so devices on either side can't see each other. That isn't one network, it's two stacked on top of each other.
Should both routers use the same Wi-Fi name?
Ideally yes, along with the same password and encryption type, so devices roam by themselves as you walk. If they differ, you have to switch networks manually every time you change rooms. What should differ is the channel.
Can I do this wirelessly, without a cable?
You can, using WDS, repeater, or wireless bridge mode, but speed at the second router drops by roughly half because one radio alternates between receiving and forwarding. A cable always gives a better result where the run is possible.
Why can't I open the second router's settings page any more?
Because its address has changed to the new one you assigned, for example 192.168.1.2, rather than its factory address. Open that new address. If you've forgotten it, press the reset button on the second router and repeat the configuration.
