How to set up modem as a wifi range extender?

Question

I want to use a DSL modem (ASUS DSL-N16) to extend the range of wifi (because of Why do different devices have different wifi reception ranges?).

I read using a DSL modem router as a wifi extender and Can I use a wireless router as a repeater?, and am looking for specific steps.

Is it possible, and how can I do it?

Answer 1

check the manual

First, check the user manual to see if your router allows it, as suggested in Can I use a wireless router as a repeater? for a different router. For the ASUS DSL-N16, it's on the ASUS website.

Search for keywords such as "bridge", "repeater", or "WDS" (Wireless Distribution System). Check on your router's user manual that it supports the same system.

change the modem's IP address

By default, modems and routers have 192.168.1.1 as the homepage IP address. A conflict will ensure from the modem having the same IP address as the router.

If that is the case, login to your modem's page to change the modem's IP. Visit http://1928.168.1.1 on a browser and login with your credentials. If you forgot, reset to factory settings and use the credentials on the back of the devices, and change the password before connecting to the internet. Go to LAN (Local Area Network) and change the IP address to 192.168.10.1 for example.

After that setup, I can access the modem's settings at 192.18.10.1 on wi-fi (though not on ethernet, which I didn't investigate further).

follow the manual's steps

I will proceed with WDS and that modem.

For the router (DrayTek in my case): Make note of the settings. On macOS, you can connect to the router's wifi, click on the wifi symbol on the menu bar with the Option key down, and see details such as:

• MAC address (also known as BSSID, e.g., 00:00:00:00:00)
• Wireless security (e.g., WPA2–Personal - AES)
• Channel (e.g., 6 (2.4 GHz, 20 MHz)).

Make also note of the wireless password of the router.

The devices should be on the same wifi channel. That modem supports only 2.4 GHz. You should probably set the same wifi channel (which is a bandwidth for the signal, e.g. channel 1 is 2401–2423 MHz).

So, for the modem: go to Wireless > General and choose wifi settings identical to those from the modem: same bandwidth (e.g., 2.4 GHz and 20 MHz), same channel (e.g., 6), same wireless security protocol (e.g., WPA2 and AES), and the same wifi password.

Then follow the steps in the user manual on the modem:

• go to the settings for WDS, such as Advanced Settings > Wireless > Bridge
• choose WDS only if you want to connect your devices to the modem via ethernet cable only, and Hybrid if you also want to connect via wifi (more details below)
• add the MAC address of the router in the remote AP list

On the router: go to the router's page, by default http://192.168.1.1, then click on Wireless LAN (2.4 GHz). Choose the Mode as bridge. The Security settings should be the same as before, e.g. pre-shared key: WPA, WPA2, AES with the same password. Add the MAC address of the modem in the list under Bridge. Check the box Connect to APs in list.

Reboot both routers. Plug a cable in either mode and you'll have internet. In hybrid mode, connect to the modem's wifi network (which you can also set), and you'll have internet. In the latter case, speed is notably slower by half, as per the manual:

In Hybrid mode, wireless devices connected to the ASUS Wireless xDSL Modem Router will only receive half the connection speed of the Access Point.

WDS-only versus Hybrid

In WDS-only mode, I was able to connect to the internet only with an ethernet cable plugged to the modem. In Hybrid mode, I was able to connect both with ethernet and wifi. (AP means "Access Point", which I assume would work if I connect the modem to the router via an ethernet cable and I did not try it.)

The manual seems to confirm these two modes, although in obscure language:

• AP Only: Disables the Wireless Bridge function.
• WDS Only: Enables the Wireless Bridge feature but prevents other wireless devices/stations from connecting to the router.
• Hybrid: Enables the Wireless Bridge feature and allows other wireless devices/stations to connect to the router.

Another manual from ASUS describes a similar result with a detailed setup:

In Hybrid mode, both wired (PC1/PC2) and wireless clients (NB1/NB2) can communicate with the other AP and its network[;] while only wired client (PC1/PC2) can communicate with the other AP and its network in WDS mode.

So I understand that WDS only is technically a bridge where the modem and the router have separate sub-networks and the "bridge" is the connection between them. Hybrid is not technically a range extender, since it creates its own wifi network, but serves the same function, and also creates congestion since you use the same wifi channel. See here for a good explanation of the difference between a bridge, a repeater, and a range extender.

pure repeater

I don't know why the modem cannot act as a simple repeater with the same wifi credentials. If anyone does or knows how to set it up, please edit or add a comment.