It often happens that after upgrading internet equipment, a user is left with a perfectly functional router, but it's no longer their primary one. Throwing away the equipment is a shame, and leaving it to gather dust on a shelf is irrational. An excellent solution is to use the old router as a network switch or access point with the wireless module disabled.
This setup allows you to significantly expand the number of wired ports in your local network without purchasing additional equipment. However, to avoid IP address conflicts and network disruptions, you must properly reconfigure the device. Simply connecting with a cable "as is" will lead to problems with internet access.
In this article, we will examine the technical side of the issue in detail, explain the difference between operating modes and describe step-by-step the process of transforming your router into a transparent network bridge. You'll learn which settings are critical and which can be ignored.
Why convert a router into a switch and what's the difference?
First of all, it’s worth understanding the terminology, since there is confusion between router And switch (switch) often leads to configuration errors. A router is a smart device that manages traffic, assigns IP addresses via DHCP, and connects different networks (local and global). A switch, on the other hand, operates at a lower level, simply transmitting data packets between devices within the same network, acting as a kind of port "extender."
Using an old router as a switch has several advantages. Firstly, it's budget-friendly: you don't need to buy a new 5-port switch if you have an old one lying around. TP-Link or AsusSecondly, it's environmentally friendly. Thirdly, many modern routers have gigabit ports, which ensure high data transfer speeds within the local network.
The key difference is that when operating in switch mode, the device stops acting as a router and becomes transparent to network requests. The main router, which is connected to the internet, takes over all control. The second device simply expands the physical availability of LAN ports.
- 📉 Cost savings: There is no need to buy new network equipment if you already have a router.
- 🚀 Network expansion: increasing the number of available ports for PCs, set-top boxes and Smart TVs.
- 🔇 Interference Reduction: Disabling Wi-Fi on the second device reduces radio frequency noise in the apartment.
Equipment preparation and compatibility testing
Before you begin setting up, you need to make sure your equipment is suitable for the task. Almost any modern router with LAN ports can be reconfigured, but there are some nuances. You'll need a primary router (the one distributing the internet) and a secondary router (the one we'll be configuring).
It's important to understand the physical connection topology. In normal mode, the ISP or modem cable is connected to a port. WAN (often blue or yellow, separated from the others). In switch mode, this port is most often unused or requires special firmware to reassign. We will only use ports LAN.
It's also worth checking the secondary device's firmware version. If it's too old, bugs may occur when disabling the DHCP server. It is recommended to update the software to the latest available version. via the web interface before starting work. This will ensure the stable operation of network protocols.
Step-by-step instructions: disabling DHCP and configuring IP
The most important step is changing the network settings of the secondary router. Connect your computer to one of the LAN ports of the device you're configuring (don't connect the ISP cable yet!). Access the web address indicated on the sticker at the bottom (usually 192.168.0.1 or 192.168.1.1).
The first thing you need to do is change IP address The router itself, so it doesn't conflict with the main device. If the primary router has an address of 192.168.1.1, then the secondary router should be assigned an address in the same subnet, but outside the DHCP range. For example, 192.168.1.250. This will allow you to always have access to the switch settings.
Then we find the section LAN → DHCP Server (or simply DHCP). Here you need to select the option Disable (Disable). This is a critical step. Leaving DHCP enabled will result in two servers handing out addresses on your network, leading to chaos: devices will constantly lose connection or be unable to connect to the network.
☑️ DHCP and IP setup
After applying the settings, the router will reboot. Since you've changed its IP address, you'll need to enter the new address (e.g., 192.168.1.250) in your browser to access the settings.
Disabling the Wi-Fi wireless module
Although our goal is to use the device as a wired switch, many people forget to disable the radio module. Even when you're not connected, it continues to emit a signal, interfering with the main Wi-Fi signal and consuming the router's processor resources, which can lead to overheating.
To disable, go to the section Wireless or Wi-FiHere you need to find the wireless network status switch and set the value Off or uncheck the box Enable Wireless RadioIn some models, for example, Keenetic or Mikrotik, you need to disable the 2.4 GHz and 5 GHz bands separately.
⚠️ Important: After disabling Wi-Fi, you will no longer be able to manage the router wirelessly. Make any changes only from a computer connected via cable, or make sure you know the device's new static IP address.
Some advanced users leave the guest network enabled for specific tasks, but for pure switch mode, it's best to completely disable the radio portion. This also improves security by closing potential attack vectors through the wireless interface.
Correct cable connection diagram
After software configuration, it's time for physical switching. A common mistake here is connecting the cable from the main router to the WAN (Internet) port of the secondary router. In our setup, this is done it is forbidden (unless you use Hotspot mode, which isn't available everywhere).
The cable from the main router (or from the modem) must be inserted into any of the ports LAN on the secondary device. The remaining LAN ports will become available for connecting your computers, TVs, and game consoles. This way, the signal passes through the device in transit.
This is what the final diagram looks like:
| Network element | Port on the main router | Port on the secondary router (switch) | Function |
|---|---|---|---|
| Provider's cable | WAN / Internet | - | Internet access |
| Connecting routers | LAN (1-4) | LAN (1-4) | Data transfer |
| PC or TV | - | LAN (2-4) | Traffic consumer |
| Laptop (setup) | - | LAN (any) | Administration |
If the internet doesn't appear on the connected devices after connecting the cable, check the indicators. The LAN indicator for the corresponding port should be lit. If only the power indicator is lit, the cable may be faulty or the port may be burned out.
What should I do if I don't have internet access after connecting?
Check if DHCP is disabled on the second router. Ensure that the IP addresses of the devices on the network are in the same subnet. Try reconnecting the cable to a different LAN port.
Possible problems and solutions
Even with proper setup, difficulties can arise. One common issue is losing access to the secondary router's interface. If you've forgotten the IP address you set, or it conflicts with another device, you'll have to Hard ResetTo do this, press and hold the Reset button on the case for 10-15 seconds while the power is on.
Another consideration is port speed. Make sure your old router supports gigabit speeds (1000 Mbps). If the ports are limited by the standard Fast Ethernet (100 Mbps), then with an Internet tariff higher than 100 Mbps, you will lose speed on all devices connected through this switch.
Thermal conditions are also worth mentioning. Routers operating 24/7 in switch mode can overheat, especially in the summer. It is recommended to periodically check the case temperature and provide additional ventilation if necessary.
⚠️ Attention: Interfaces and names of menu items may differ depending on the model and firmware version (for example, in Asus this is the "Administration" section, and in TP-Link — "System Tools"). Always consult the manufacturer's official documentation.
FAQ: Frequently Asked Questions
Is it possible to use the WAN port of the secondary router to connect to the main one?
In the standard "switch" configuration, this won't work; it would create a double NAT and disrupt the network. However, if the router has an "Access Point" mode, you can connect the cable to the WAN, and the system will automatically reconfigure the ports.
Will my internet speed decrease when using an old router?
The speed won't drop if the LAN ports support 1 Gbps (Gigabit Ethernet). If the ports are older (100 Mbps), the speed will be throttled to 100 Mbps on all devices connected through them.
Do I need to set up a Wi-Fi password if I disabled it?
No, if the Wi-Fi module is software-disabled, it doesn't emit a signal and a password isn't required. However, in case someone else resets the settings, it's best to change the web interface administrator password to a strong one.
Is it possible to connect two routers via Wi-Fi and then distribute the Internet via cable?
Yes, this is called "Client" or "WDS" mode. But in this case, the device won't function as a simple switch; it will use a radio channel, which will reduce the overall network throughput by half.