Using an old router as a switch or access point is a great way to save money and extend your home network's coverage without buying new equipment. Users often have some left over. TP-Link, Asus or D-Link, which are outdated but are quite capable of functioning as a powerful switch or repeater. Converting the device into a simple switch with wireless data transfer allows you to connect wired devices into a single network and distribute internet over the air in areas where the main access point's signal is weak.
The method involves changing the router's default operating mode. Instead of creating a new subnet and assigning IP addresses, it becomes a transparent bridge, forwarding traffic from the main gateway. This solution is ideal for large apartments, private homes, or offices where a cable needs to be extended to a remote room to provide multiple LAN ports and stable Wi-Fi. Proper configuration eliminates address conflicts and ensures seamless operation of the entire infrastructure.
Unlike purchasing specialized equipment, repurposing an existing gadget doesn't require any financial investment, but it does require careful network configuration. All you need is an Ethernet cable, a computer, and access to the device's web interface. The main difference between a switch and a router in this context is the lack of NAT and IP address distribution (DHCP) on the second device. Below we will cover in detail all the stages of preparation, configuration, and connection.
Equipment preparation and compatibility testing
Before you begin the software, you need to ensure your hardware is physically suitable for upgrading. Not all router models are equally suited for bridge or switch mode. Multiple ports are critical. LAN, as these are the ports that will be used to connect end devices. If the router has only one port (often shared with the WAN port), turning it into a full-fledged switch won't work without some complex soldering.
Check the technical condition of the device. Old power supplies can swell or produce unstable voltage, leading to constant disconnects. It's also worth inspecting the antennas: if they're loose or damaged, the wireless signal will be poor. For a Wi-Fi switch to work, the radio module's stability is crucial, as in older models, it can degrade over time.
Make sure you know the device model and its hardware version. Firmware for versions v1 and v2 may differ, and installing the wrong firmware will cause damage. You can find this information on the sticker on the bottom of the device. Also, prepare an Ethernet cable to connect the main router to the one you're repurposing. For maximum speeds, it's best to use a Category 1 cable. Cat5e or Cat6.
Setting up the main router and network addressing
For the "main router + switch" combination to work correctly, you need to clearly understand your network structure. The main router (gateway) should already be configured and distributing the internet. You need to know its IP address, which usually looks like this: 192.168.0.1 or 192.168.1.1This is the address we'll use to assign a static IP address to our future switch.
It's recommended to reserve an IP address for the new device in the main router's DHCP settings, although this isn't strictly necessary if you manually assign a static address on the switch itself. The main rule: the second device's address should be in the same subnet, but not the same as the gateway address or within the dynamic range to avoid conflicts. For example, if the gateway 192.168.1.1, and DHCP distributes with 100 By 200, then the switch can be given 192.168.1.2.
It's also a good idea to set the channel and bandwidth for the Wi-Fi network on your primary router if you plan to use it with a second device in the same room. This will help reduce interference. However, if the second router is in a different room, you can leave the channel settings on automatic or experiment with them later to minimize frequency collisions.
⚠️ Attention: Router interfaces are constantly updated by manufacturers. The layout of menu items may differ from what's described. If you can't find the option you need, search for a similar option or refer to the documentation on the official website of your model's manufacturer.
Changing the IP address and disabling the DHCP server
This is the most important step in the instructions, as it determines the functionality of the entire setup. Connect your computer to the LAN port of the router you're configuring (without connecting it to the main one yet). Access the web interface using the address on the sticker. First, change the IP address of the device itself. Find the section Network (Network) -> LANIn the IP Address field, enter the static address you selected earlier, for example, 192.168.1.2.
After saving the settings, the router will reboot, and you will need to re-enter the interface using the new address. Now you need to disable the DHCP function. Find the section DHCP Server and select the option Disable (Disable). This is a critical step: If you leave DHCP enabled, a second address distribution server will appear on your network, which will lead to chaos: devices will receive incorrect gateways and lose internet access.
☑️ LAN and DHCP setup
After disabling DHCP, the router will stop functioning as a router and will act as a transparent switch. All requests for IP addresses from devices connected to it will be ignored by this device and will reach the main router, which will then assign the correct settings. Leave the subnet mask at its default value, which is usually 255.255.255.0.
Setting up a wireless Wi-Fi network
Now let's set up the wireless part. Go to the section Wireless (Wireless Mode). Here you need to set the network name (SSID). You can name the network the same as your main one to create the illusion of a single space, or give it a unique name so you know which access point you're connected to. For maximum compatibility with older devices, leave the network mode set to [Default]. Mixed or 802.11 b/g/n.
Pay special attention to security. Choose the encryption type WPA2-PSK (or WPA3(If your device supports it). Create a strong password. If you decide to share the same network name (SSID) as your main router, make sure the passwords and encryption types are identical. This will allow devices to automatically switch between access points, although true roaming (802.11r/k/v) will not work on older devices.
Should I make the network names (SSID) the same?
Using the same name makes sense if the access points are located far apart. If they're close together, the phone might lock onto the farther router with a weak signal while ignoring the nearby one with a strong one. In such cases, it's better to give the network a unique name, for example, "Home_Living" and "Home_Bedroom."
It is also recommended to manually select the broadcast channel. If the main router operates on channel 1, it is better to assign the second device to channel 6 or 11 to avoid overlapping. In an apartment building, the channel width for the 2.4 GHz band is often best set to 20 MHz for stability, even if the speed is lower.
Physical connection and wiring diagram
After the software setup, let's move on to the cables. Take an Ethernet cable. Plug one end into any available space. LAN-port of the main router. Connect the other end to LAN-port of our converted device. Important: port WAN The (Internet) port on the second router is not used in this setup and should be left empty. Using the WAN port will create double NAT and isolate the second router's devices from the general network.
The connection diagram looks like this: Internet -> Primary Router (LAN) -> Cable -> Secondary Router (LAN). Now the second router functions as a Wi-Fi switch. All devices connected to its LAN ports or wirelessly will receive IP addresses from the primary router and will be able to see each other on the local network (printers, NAS, media players).
| Parameter | Main router | Second router (Switch) |
|---|---|---|
| IP address | 192.168.1.1 | 192.168.1.2 (Static) |
| DHCP Server | Enabled | Disabled |
| Connecting the cable | LAN port | LAN port (WAN not used) |
| Function | Gateway, IP Distribution | Switch, Access Point |
If the LAN indicators on both devices light up or blink after connecting, there's physical contact. The computer connected to the second device should automatically obtain an IP address from the primary router's range and connect to the internet. You can check this with the command ping 8.8.8.8 in the command line.
Optimization and troubleshooting
After the system is launched, some issues may arise. If you have internet access but the speed is slow, check the cable quality. Cheap or damaged cables can drop the connection speed to 100 Mbps or even 10 Mbps. The speed should be indicated in the port status in the router interface. 1000 Mbps (if the equipment is gigabit) or 100 Mbps.
If devices aren't receiving IP addresses, double-check the DHCP setting on the second router. Make sure it's truly disabled. Sometimes rebooting the entire chain helps: first turn off the primary router, then the second router, turn on the primary router, wait for it to boot, and only then turn on the second router. Also, check whether the second router's firewall is blocking incoming connections from the local network (although this is rare with DHCP and NAT disabled).
To prolong the life of your device, ensure it has good ventilation. Older routers can become very hot when operating 24/7. Avoid placing them on soft surfaces or in direct sunlight. If the device is operating as an access point in 2.4 GHz mode, the radio module may become significantly hot.
⚠️ Attention: When using older models (for example, those with the 802.11n standard), Wi-Fi speeds may be limited to 150-300 Mbps under ideal conditions. Actual speeds will be lower due to airborne losses. Don't expect gigabit speeds over the air from 10-year-old equipment.
Frequently Asked Questions (FAQ)
Is it possible to use the WAN port on the second router in this setup?
No, the WAN port is not used in the "router as a switch" configuration. Connecting it will create a separate subnet, and devices on the second router will not be able to see devices on the first. The cable should be plugged into the LAN ports only.
Will devices connected to different routers see each other?
Yes, since there's only one DHCP server (on the main router) and NAT is disabled on the second device, all devices are on the same local subnet. You'll be able to print to a network printer or stream video to a TV regardless of which router they're connected to.
What should I do if I forgot the new IP address of the second router?
You'll need to reset the device. Afterward, it will revert to the factory IP address (indicated on the sticker), and you'll need to repeat the setup process. To avoid this, write down the new IP address on the sticker on the device.
Will a second router slow down my internet speed?
If you use a wired connection between the routers, speed losses are minimal. However, if you use the second router as a repeater (without a cable), speed will drop by at least 50%, since the radio channel operates in half-duplex mode. In the described cable setup, speed is limited only by the port capabilities (100 Mbps or 1 Gbps).