Router as a Wi-Fi Switch: Diagrams and Configuration

Using an old or spare router as a wireless access point switch is an effective way to expand a local network without purchasing expensive equipment. Users often face situations where the main router isn't sufficient to cover all rooms, or the number of LAN ports is limited. Instead of purchasing new devices, you can use the one you already have. router, turning it into a transparent network node.

This configuration allows you to combine wired devices into a single network and simultaneously distribute a Wi-Fi signal, while the primary router remains the control center. This solution is ideal for setting up a wired connection for Smart TVs, gaming consoles, and desktop PCs in remote rooms. It's important to understand that in this scenario, the second device ceases to function as a gateway and operates exclusively at the data link layer of the OSI model.

Before you begin physically connecting cables, you need to clearly understand the differences between the operating modes of network equipment. Router manages data flows between different networks (WAN and LAN), distributes IP addresses via DHCP and provides firewall protection. Switch A switch simply forwards packets between devices within the same network without interfering with addressing. Converting a router into a switch requires disabling its routing functions.

A key task when repurposing equipment is to prevent IP address conflicts. If both devices attempt to assign addresses to network clients or have the same gateway address, the network will crash. The main rule: the IP address of the secondary router must be in the subnet of the primary one, but not the same as it, and the DHCP service on the secondary device must be completely disabled.

Differences between a router and a switch in the context of network expansion

Understanding the architectural differences is critical for proper configuration. A router is an intelligent device that analyzes packet headers and makes decisions about where to forward them. It creates a local area network (LAN) and connects it to the wide area network (WAN). A switch, on the other hand, is dumber, but faster within a segment: it simply knows which port corresponds to which MAC address and forwards frames directly.

When we configure a router as a Wi-Fi switch, we essentially disable its "brains" (NAT, routing, DHCP) and leave only the "switch matrix" and radio module. In this mode, the WAN (Internet) port on the secondary device is usually left unused, as all traffic goes through the LAN ports. This turns the device into a simple port extender and wireless bridge.

This approach has several advantages over repeater mode. A repeater cuts the wireless connection speed in half because the radio module simultaneously receives and transmits data. In the "router as a switch" approach, devices are connected via cable, providing gigabit speeds, and Wi-Fi is distributed regardless of how much bandwidth is consumed by data transfers between routers.

There are several scenarios where this scheme is most justified:

• 🔌 Lack of LAN ports: When you need to connect more devices via cable than there are outputs on the main router.
• 📡 Improving Wi-Fi coverage: Installing a second device in a distant room with a long cable connection for a stable signal.
• 💻 Segmentation of wired devices: Connecting equipment in different parts of the apartment into a single local network for file sharing or DLNA.

Preparing equipment and resetting settings

Before starting work, you need to physically prepare the secondary router. It's crucial to start with a clean slate, as the "out of the box" configuration or any remaining ISP settings may cause conflicts. Locate the "Put" button on the device's body. Reset (often recessed into the housing). Press it with a paper clip for 10-15 seconds until the indicators flash simultaneously.

After the reset, connect your computer to any LAN port of the secondary router using a cable. Do not connect the WAN cable from the primary router or modem yet! Access the web settings interface by entering the address on the sticker on the bottom of the device (usually 192.168.0.1 or 192.168.1.1). The login and password are also indicated on the label, most often it is admin/admin.

Make sure your computer is receiving an IP address automatically. If you can't access the interface, check your PC's network card settings. In some cases, especially with older models, TP-Link or D-LinkYou may need to statically assign a network address to your computer in the same subnet as your router. Once you've successfully logged in to the control panel, you can begin changing network settings.

Setting an IP address and disabling DHCP

The most important step is setting up the addressing. You need to change the LAN IP address of the secondary router so that it doesn't conflict with the primary one. If the primary router has an address 192.168.1.1, then the secondary one needs to be assigned an address from the same subnet, but unique, for example, 192.168.1.254 or 192.168.1.2.

Find the section Network → LAN (or similar, depending on the firmware). Enter the new address in the IP Address field. After saving the settings, the router will reboot, and you will need to log in to the interface again using the new address. Remember this address; you will need it for future device management.

Next comes the critical step of disabling the DHCP server. Find the section DHCP or DHCP Server. Select an option Disable (Disable) and save the settings. Now the secondary router will stop distributing IP addresses to connected devices; this function will be performed only by the primary router. All clients will receive addresses from a single pool assigned to the primary gateway.

⚠️ Attention: After disabling DHCP and changing the IP address, you will lose connection to the router if your computer has a static IP address. Make sure your PC is set to obtain an IP address automatically (DHCP Client) to continue setup.

If the secondary router has Operation Mode settings, select the mode Access Point (Access point) or Bridge (Bridge). In modern models Keenetic, Asus or Mikrotik This automates the process: the system will automatically disable DHCP and reassign ports. Budget models may not have this mode, requiring manual IP and DHCP configuration.

Setting up a wireless network (Wi-Fi)

After setting up the network, we move on to the wireless module. In the section Wireless or Wi-Fi Set a network name (SSID). You can name it the same as your main network so devices can switch automatically (roaming), or give it a unique name, such as "Office_WiFi_Ext."

To ensure security, select the encryption type WPA2-PSK or WPA3, if the equipment supports it. The password must match the main password if you want seamless roaming, although technically these are two different devices, and the handshake when switching will occur with a slight delay. Set your region of residence for proper channel operation.

It's important to select the right wireless channel. If your primary router operates on channel 1, it's best to assign the secondary router to channel 6 or 11 to avoid overlapping, especially in the 2.4 GHz band. In the 5 GHz band, channels are wider and fewer in number, so it's important to avoid exact overlaps if possible.

Physical cable connection diagram

Once the software setup is complete (IP changed, DHCP disabled, Wi-Fi configured), you can proceed to the final connection. Take a patch cord (network cable). Connect one end to any LAN port main router.

Connect the other end of the cable to secondary routerThere is an important nuance here that depends on the model:

• 🔹 Classic scheme (for most older routers): The cable is connected in LAN port secondary router. The WAN port remains free. This is how the device functions as a switch.
• 🔹 Modern design (Asus, Keenetic, TP-Link with AP mode): If the "Access Point" mode is selected in the settings, the cable can (and sometimes should) be connected to WAN portThe device will redirect the streams automatically.

If you haven't used automatic AP mode, use a LAN-to-LAN connection only. After connecting the cable, the port indicators should light up or blink, indicating a link is established. Devices connected to the secondary router via cable or Wi-Fi should now receive IP addresses from the primary router and have internet access.

Diagnosing and troubleshooting

If the internet still doesn't work after connecting, check the addressing chain. The computer connected to the secondary router should receive an IP address like 192.168.1.XXX (where 1 is the primary router's subnet), and the gateway must be the primary router's address. If the gateway is the secondary router's address, DHCP is not disabled.

A common problem is a network loop or IP conflict if you forgot to change the secondary device's address to a unique one. Also, make sure the cable is intact. For gigabit speeds (1000 Mbps), all 8 wires in the cable must be intact. If the cable is 4-wire, the speed will be limited to 100 Mbps.

What should I do if I can't access the secondary router's settings?

If you've changed your router's IP address but forgotten it, or it's lost, the only solution is to reset it again using the Reset button. Afterward, the router will revert to the factory IP address listed on the sticker, and you'll have to repeat the IP and DHCP setup process. To avoid this, write the new IP address directly on the device with a marker.

Features of customization for different brands

Interfaces from different manufacturers differ, but the logic remains the same. In devices TP-Link look for the tab Network -> LAN to change IP and DHCP to disable it. In new Tether or cloud interfaces, there is a mode switch in Operation Mode.

Routers Asus have a very convenient switch in the admin panel: Administration -> Opening hours -> Access point (AP)When you select this option, the system will prompt you to configure the settings, and manually disabling DHCP may not be necessary—the system will do it automatically.

In equipment Mikrotik (RouterOS) the problem is solved by removing the NAT rule and DHCP service, as well as adding ports to one bridge (Bridge). This is a more complex but flexible option for advanced users, allowing fine-tuning of traffic filtering even in switch mode.

⚠️ Attention: Firmware interfaces may be updated by the manufacturer. The menu item locations may differ from those described. Search for keywords: LAN, DHCP, IP Address, Operation Mode. If you can't find the item you need, consult the official manual for your specific model.

Safety and final recommendations

Remember that a router converted into a switch is still a network device with open management ports. Be sure to change the default administrator password (admin) to a complex one. Even if DHCP is disabled, an attacker connected to your Wi-Fi network can access the secondary router's control panel if the factory password remains.

Place the secondary device so it doesn't overheat. They're often hidden in low-voltage enclosures where there's no ventilation. To operate as a Wi-Fi switch, the antennas should be extended and pointed vertically upward for better coverage.

Using an old router as a Wi-Fi switch is an eco-friendly and cost-effective way to improve your home network. You get additional ports and a stable signal without spending money on new hardware. Just be sure to carefully monitor IP addresses and avoid running two DHCP servers on the same network.

Is it possible to use the WAN port of a secondary router?

In manual DHCP disable mode (classic switch), the WAN port is typically not used, as it is dedicated to receiving internet from the ISP and is often isolated from the LAN ports by internal routing. However, if the router has a software-based "Access Point" mode, using the WAN port becomes possible and even preferable, as the system automatically reconfigures the port logic.

Will the internet speed decrease through such a switch?

With a wired connection, the speed won't drop at all if the cable is in good condition (Cat5e or Cat6) and the ports are gigabit (1000 Mbps). If the ports are FastEthernet (100 Mbps), the speed will be limited to 100 Mbps. With Wi-Fi, the speed will depend on the signal quality and standard (N, AC, AX), but it won't be halved, as in repeater mode, since the backhaul (the communication channel between the routers) is wired.

Will devices see each other on the network?

Yes, all devices connected to the primary and secondary routers will be on the same local network (the same subnet). You'll be able to transfer files via SMB, use printers, stream video to your TV (DLNA/AirPlay), and access network-attached storage (NAS) devices without restrictions, as they're logically on the same network.