How to connect an old router to a new router via Wi-Fi

It often happens that after purchasing modern high-speed equipment, users are left with a perfectly functional but outdated router that they're too embarrassed to throw away. Instead of letting it gather dust on a shelf, you can turn it into a useful networking tool, such as an access point or a repeater to boost the signal in distant rooms. This solution allows you to expand your wireless network coverage without running long and unsightly cables throughout your entire house or apartment.

Connecting two devices over the air isn't just a cost-saving measure, it's also a great way to create a seamless network where devices automatically switch between signal sources. However, the setup process requires an understanding of IP address logic and wireless module operating modes. In this article, we'll detail a process that will help you revive an old device and integrate it into your current infrastructure.

Before starting software configuration, you need to ensure hardware compatibility. Not all models support bridge or repeater modes, especially with very old firmware versions. It's also worth remembering that connection speed on the secondary network will depend on antenna power and standard support. IEEE 802.11ac or ax.

Choosing the optimal operating mode for an old router

The first step toward creating a distributed network is determining what function your old router will perform. Most modern, and even older, firmware versions support multiple use cases, each with its own specific features and speed limitations.

The most popular option is the mode Repeater A repeater simply receives the signal from the main router and retransmits it further, increasing the coverage range. However, this method often results in a 50% reduction in speed, as the radio module operates in half-duplex mode, alternately receiving and transmitting data.

A more advanced solution is the mode WDS Bridge A bridge allows you to connect two routers into a single logical network, where all devices are on the same subnet and can see each other. This is ideal for sharing files or network printers connected to one of the devices.

• 📡 Repeater - simple expansion of the coverage area, suitable for watching videos and surfing, but reduces the overall channel capacity.
• 🌉 WDS Bridge — the unification of network segments, requiring configuration at both ends, preserves the structure of the local network.
• 📶 Client Mode — turns the router into a receiver for connecting wired devices (Smart TV, consoles) to Wi-Fi.
• ⚡ Access Point - access point mode, which usually requires a cable connection, but some models allow you to raise it via Wi-Fi.

It is important to understand that the names of the modes may differ depending on the manufacturer and software version. TP-Link it may be called "Wi-Fi signal booster" Asus - "Media bridge mode", and Mikrotik will require manual protocol configuration Station.

Preparing equipment and resetting settings

Before making any changes to network settings, it's critical to reset the secondary device to its original state. Old configurations, saved passwords, and static IP addresses can cause address conflicts on the network, resulting in a complete loss of internet access.

Find the button on the body of the old router Reset or WPS/ResetIt's usually recessed into the housing to prevent accidental pressing. To activate the reset, plug the device into a power outlet, wait about a minute for the boot process to complete, and then press the button with a thin object (a paperclip or toothpick) for 10-15 seconds.

⚠️ Note: The indicators on the case may flash simultaneously or go out during the reset. This is a normal system response to the factory reset command.

After the device reboots, it will be ready for the new configuration. Connect to it from a computer or smartphone by finding the network name listed on the sticker on the bottom of the device. By default, the password is also listed there, unless it has been changed previously.

Now you need to find the MAC address of the new (main) router to which the old one will connect. This is the unique identifier of the network card, which is needed to configure filtering or bridging. You can do this by looking at the sticker on the bottom of the main router or by logging into its web interface.

Setting up an IP address and local network

One of the most common errors when connecting two routers is an IP address conflict. By default, most devices have an IP address 192.168.0.1 or 192.168.1.1If both devices have the same address, the network will not work.

You need to change the IP address of the old router so that it is in the same subnet as the main router, but not the same. For example, if the main router has the address 192.168.1.1, then the old one needs to be assigned 192.168.1.2 or any other free address in this range.

Go to the web interface of the old router, go to the section Network (Network) -> LAN (Local Area Network). In the field IP Address Enter the new address. Leave the subnet mask unchanged, usually it is 255.255.255.0.

After changing the IP address, the device will ask you to reboot. From now on, you will have to use the new address to access the old router's settings. Don't forget to also disable DHCP server On an older device, if you configure access point or bridge mode so that only the main router distributes addresses.

Why disable DHCP on the second router?

If you leave DHCP enabled on both devices, they will assign IP addresses to connected clients independently. This will lead to conflicts: a device might receive an address from the old router, but its gateway will point to the new one, preventing internet access. In repeater mode, DHCP is often disabled automatically.

Wireless bridging (WDS)

WDS (Wireless Distribution System) mode allows you to connect two routers wirelessly, creating a transparent bridge. For this technology to work successfully, both devices must support this standard, although manufacturers often implement it differently, which can cause complications when mixing brands.

In the wireless settings (Wireless) select the type of work WDS Bridge or just tick the box Enable WDSAfter this, a "Search" or "Survey" button will appear. Clicking it will display a list of available networks. Select the network of your main router.

The key here is to ensure the encryption parameters match exactly. The security type (WPA2-PSK, WPA3) and password must be identical on both devices. Even one incorrect character will result in the connection failing, although the indicators may show activity.

• 🔒 Make sure the channels (Channel) on both routers are fixed at the same value, and are not in the "Auto" mode.
• 📡 Channel width (Channel Width) must also match, for example, 20 MHz or 40 MHz.
• 🔑 The passphrase must be entered in the corresponding WDS or Pre-Shared Key field.

After saving the settings and rebooting, try not to change the SSID (network name) on the old router if you want devices to switch seamlessly, or set a unique name to identify which base station you're connected to. You can check the connection with the command ping in the command line.

⚠️ Note: Firmware interfaces are constantly being updated. The menu item layout may differ from that described. If you don't find an exact match, look for sections with the words "Bridge," "Relay," or "Repeater."

Setting up security and filtering

Security is paramount when setting up a wireless bridge, as you are effectively extending the perimeter of your network. Using legacy encryption protocols such as WEP or WPA (without the two), makes your network vulnerable to hacking in a matter of minutes.

It is recommended to use the standard WPA2-PSK (AES) or, if the equipment supports it, WPA3Make sure the function is disabled on your old router. WPS (Wi-Fi Protected Setup), as it contains known vulnerabilities that allow attackers to easily guess the PIN code.

For an additional layer of security, you can configure MAC address filtering on the main router. This will cause the main router to only allow devices with whitelisted addresses onto the network. You'll need the MAC address of the old router's WAN port or wireless interface.

ip neigh show dev wlan0

This command on Linux-based systems (or the equivalent in the router console) can help you see neighboring devices on the network. However, for the average user, it's enough to simply copy the MAC address from the sticker or from the web interface of the old device and add it to the main router's settings in the "MAC address" section. Wireless MAC Filter.

Troubleshooting and Speed ​​Optimization

After setup, you may encounter a situation where the network is active, but the internet is not working or is extremely slow. First, check the event log (System Log) on both routers. There may be entries about association errors or incorrect passwords.

A common issue is incorrect time setting or desynchronization, although this isn't critical for a basic connection. More importantly, check whether the old router is receiving an IP address from the main router. The connection status should indicate that the connection is established and an IP address has been obtained.

If your speed is low, try changing the broadcast channel. In apartment buildings, the airwaves are often clogged with signals from neighboring networks. Use Wi-Fi analyzer apps on your smartphone to find the least congested channel and set it in both router settings.

⚠️ Please note: Speeds in wireless bridge or repeater mode will always be lower than those with a wired connection. Losses can range from 30% to 50% of the actual speed of your provider's plan due to protocol overhead and half-duplex operation.

Physical obstacles should also be considered. Walls, mirrors, and household appliances (such as microwaves) significantly reduce signal strength. Place the old router within line of sight of the new one, but in a position that allows it to cover the dead zone.

Is it possible to connect routers from different manufacturers (for example, TP-Link and Asus)?

Technically, WDS mode is a standard, but in practice, each manufacturer implements it differently. Connecting routers from different brands in bridge mode (WDS) isn't always possible. However, Repeater mode often works cross-platform, as it's more standard. If WDS doesn't work, try Client mode on your old router.

Will the internet work if the main router is turned off?

No, in the described setup, the old router acts only as a repeater or access point. It doesn't have its own internet connection. All requests from devices connected to the old router go through the main router. If the main router is turned off, the local network between devices may work (if static addressing is configured), but there will be no access to the global network.

Will my internet speed decrease when connecting through a second router?

Yes, a speed drop is inevitable. With a wireless connection, the "air" is split in half: one time is spent receiving data from the main router, the other is spent transmitting it to the client. Interference and distance also play a role. Expect a 30-50% speed drop compared to a direct connection to the main router.

Do I need to flash my old router before setting it up?

Not required, but recommended. Firmware update (Firmware) may add support for new encryption standards, fix security bugs, and improve the stability of the wireless module. Before updating, be sure to read the instructions for your specific model to avoid bricking your device.