Old routers are rarely thrown away right away, especially reliable models like D-Link DSL-2640UOften, they just sit on a shelf until the signal drops again in a distant room. Using this device as a full-fledged access point is a great budget-friendly option. You get a stable wireless signal without buying new equipment.
Turning your router into an access point allows you to expand your home network's coverage area. The main difference from router mode is that DSL-2640U It stops assigning IP addresses and managing traffic. It simply relays the signal from the default gateway. This simplifies the network structure and eliminates address conflicts.
In this article, we'll cover all the intricacies of interface configuration. You'll learn how to properly connect cables and which settings to change in the web menu. Even if you have no administration experience, following the instructions will allow you to get the system up and running in 15 minutes.
Equipment preparation and compatibility testing
Before you go into settings, make sure your equipment is working properly. Model D-Link DSL-2640U There are many variations (N, NRU, U, S), but the basic operating principle is similar. You'll need the router itself, a power supply, and an Ethernet patch cord. It's best to connect your computer via cable for setup to avoid connection interruptions during the process.
Check your device's firmware version. Older versions may be unstable or contain security vulnerabilities. If your router has been sitting idle for several years, it's a good idea to update the firmware through the manufacturer's official website. This will take time, but will ensure stable operation of the wireless module.
⚠️ Important: Before starting any adjustments, be sure to perform a full reset. Press and hold the button on the back panel for 10-15 seconds until the indicators blink. This will prevent conflicts between old configurations and the new connection scheme.
It's also worth checking the integrity of the LAN ports. In access point mode, the WAN port (ADSL) will not be used. All connections are made only through the yellow LAN ports. Make sure at least one of them is working properly and is not corroded.
Setting up the main router (Master)
For the router + access point combination to work correctly, the main device must be configured correctly. This is the one that will assign IP addresses to all clients. Go to the main router's interface and find the section LAN or Network Settings.
You need to remember or write down the gateway IP address. This is usually 192.168.0.1 or 192.168.1.1The DHCP server's address range is also important. If the main router assigns addresses from 100 to 200, then the access point should be assigned a static IP outside this range, for example, 192.168.0.2.
Pay attention to the wireless network channel. If you plan to use multiple access points, the channels should not overlap. For the 2.4 GHz band, channels 1, 6, and 11 are optimal. This minimizes signal interference.
DSL-2640U LAN interface configuration
Now let's move on to setting up the app itself. D-Link DSL-2640UConnect your computer to any LAN port of the device. By default, the web interface address is 192.168.1.1Login and password are most often adminIf the addresses don't match your PC's network, temporarily change the IP address on your computer manually.
In the menu, go to the section Network -> LANHere you need to change the router's IP address. It must be in the same subnet as the main router, but unique. For example, if the gateway 192.168.1.1, then we set the access point 192.168.1.2We leave the subnet mask as default. 255.255.255.0.
A critical step is disabling the DHCP server. Find the tab DHCP Server and uncheck the box EnableOnly one DHCP server should be running on the network (on the main router). Leaving it enabled on both devices will cause IP conflicts, and all clients will lose internet access.
After changing the IP address, the router will prompt you to reboot. Your computer will lose connection to the device because the subnet has changed. You'll need to reset your PC's network settings to automatic or enter a new static address in the required range to continue setup.
☑️ Checking LAN settings
Setting up a wireless WiFi module
Let's move on to the most important part - setting up the radio module. In the menu Wireless -> Basic Make sure the wireless network function is turned on (Enable Wireless). The SSID (network name) can be set to the same as your main router for seamless roaming, or a unique one to help you understand which access point you're connected to.
In the section Security select encryption type WPA2-PSKThis is the most secure and compatible standard for home devices. It's best to make the passphrase (pre-shared key) complex but memorable. Avoid using outdated WEP encryption, as it can be cracked in minutes.
Pay special attention to the channel selection. In the section Channel select a value Auto Or fix a specific number (1, 6, or 11). Fixing the channel often provides a more stable result, since the router won't constantly search for the "best" path and interrupt the connection.
Why can't I use WPA3 on older models?
The D-Link DSL-2640U model belongs to the previous generation of WiFi standards (802.11n/g). The hardware of these devices does not support modern WPA3 encryption algorithms. Attempting to enable them is impossible, and using mixed mode may reduce speed.
Physical cable connection diagram
After software setup, you need to properly connect the devices with wires. A common mistake here is connecting the cable to the WAN port. In access point mode, the ADSL (WAN) port D-Link DSL-2640U is not used. It remains free.
Take a patch cord. Insert one end into any free one. LAN port main router. We insert the other end into any LAN port (1, 2, 3, or 4) configurable D-Link ports. This turns the router into a simple switch with WiFi functionality.
The table below shows the differences in connection for different operating modes:
| Parameter | Router Mode | Access Point Mode |
|---|---|---|
| Cable from the provider | To the ADSL/WAN port | Not used |
| Cable from the main network | Not used | To LAN port (any) |
| DHCP Server | On | Turned off |
| IP Address | Unique subnet | In a subnet of the main network |
After connecting the cables, reboot both devices. The computer or smartphone connected via WiFi to the new access point should receive an IP address from the main router. The test is successful if there is internet access and local network connectivity.
⚠️ Note: Firmware interfaces may differ depending on the hardware revision (Ver.C1, D1, U). If you don't see the described options, look for similar names (e.g., Bridge Mode or AP Mode).
Diagnostics and troubleshooting
If the internet still isn't working, check the signal chain. First, make sure the LAN indicator on both routers is lit or blinking. No port activity indicates a broken cable or faulty port.
Try pinging the gateway. Open a command prompt and enter ping 192.168.1.1 (the main router's address). If packets are being lost, the problem is with the radio channel or cable. If you can ping but websites aren't loading, check your DNS settings.
A common problem is an IP address conflict. Make sure you haven't assigned the access point an address that's already taken by another device on the network (such as a network printer or camera). The static IP of the access point must be reserved outside the DHCP distribution range of the main router.
Network optimization and security
After a successful launch, do not forget to change the password for logging into the web interface itself. D-Link DSL-2640U. Standard admin/admin This is a security hole. Anyone who connects to your WiFi can change settings or disable your internet connection.
To improve speed, it is recommended to disable older standards. In the wireless settings (Wireless Mode) select 802.11n only or 802.11g/n mixed, unless you have very old devices. Disabling Mode B (802.11b) will significantly increase overall throughput.
Regularly check the list of connected clients in the status bar. This will help identify uninvited guests. If you notice an unknown device, change your WiFi password and refresh the login page.
Can DSL-2640U be used as a repeater?
This model doesn't officially support repeater mode (WDS) in most standard firmware revisions. It only functions as a wired access point. Wireless network expansion requires third-party firmware (if available for your version) or the purchase of a specialized repeater.
Is it possible to connect routers via WiFi without a cable?
The D-Link DSL-2640U model's stock firmware doesn't support wireless client or repeater functionality. Wireless LAN (WDS) is required for a wireless connection (bridged), which is often missing or unstable on this model. A wired LAN-to-LAN connection is recommended for guaranteed speeds.
What is the maximum speed through this access point?
Model DSL-2640U Refers to the 802.11n standard. The theoretical speed is up to 150 Mbps (with one antenna) or 300 Mbps (with two). In real-world conditions, taking into account interference and distance, the actual WiFi speed will be around 40-70 Mbps. LAN ports are limited to 100 Mbps.
What should you do if you forgot your hotspot password?
The only way to restore access is to perform a hard reset. Locate the hole on the back panel, press it with a paperclip, and hold it for 10-15 seconds while the power is on. After this, the device will return to factory settings (IP 192.168.1.1, login admin, password admin), and you will have to repeat the configuration.