I bought a Asus DSL-N55U Annex A router a few years back when my old ADSL router from the telco broke down. It is a solid router and did not give any problems. Since I have just upgraded to Viewquest Fibre, it seems that is no more need for the DSL-N55U router. Wasted really. However with my new Asus RT-AC88U at the far end of the house. I will need another Access Point (AP) at the other corner of the house to get better coverage. Should i get another Access Point/ router or perhaps just use the DSL-N55U router?

Assuming at the far end you already have a LAN connection, you could configure the Asus DSL-N55U Annex A as an Access Point. I do not recommend buying a WIFI extender. A WIFI extender halves your WIFI bandwidth and stability can be an issue.

Trial Setup A (Not successful for me)

Searching online I seem to find a lot of links to try the following with the latest ASUS DSL-N55U firmware.

Without deleting your setup and before connecting the DSL-N55U to your new network, you could try going to http://xxx.xxx.xxx.xxx:8080/Advanced_OperationMode_Content.asp. Click on Access Point (AP) mode, then save it.

The next screen will pop up and you can key in the necessary details

However at the next screen there is no way to go through as it will detect the ADSL connection, which will not time out. Click on Home to leave this page.

Some other online users claim that if successful, this will turn DHCP off and then convert any of the 4 LAN ports to a WAN port but i had no luck in this setup. Basically once you reboot the router it returns to the default wireless router mode (Default). So Trial Setup A doesn’t work for me.

Trial Setup B (Successful but buggy)

Another set of articles I found online advised to do the following:

1. Connect a PC to the DSL-N55U first.
2. Make sure your WIFI SSID and passwords have been configured.
3. Under Advanced Settings -> LAN-> Set a LAN IP which will not conflict with your new router IP Address and it has to be in the same subnet. (For example, assuming your new router’s IP is 192.168.1.1, the Asus DSL-N55U cannot have this IP and should use 192.168.1.2)
4. Under Advanced Settings -> LAN -> Turn off DHCP on the Asus DSL-N55U
5. Remove and plug the DSL-N55U into your new router. All DHCP will come from your new netowork router.

This setup works however i noticed after sometime WIFI connections tend to have problems getting an IP address from your main router. Rebooting the DSL-N55U is the only way but it becomes tiring to do so a few times in a day.

Trial Setup C (Successful!)

I decided to try something different, with some trial and error, i configured my Asus DSL-N55U as below

1. Assuming you had done Trial B, On the DSL-N55U, Under Advanced Settings -> LAN-> Turn on DHCP again and apply
2. Disconnect the Asus DSL-N55U from your new Network and connect it to a PC.
3. Since DHCP is on -> Go to Advanced Setting -> LAN -> Now make sure your IP is not in the same range as your new network. Assuming your new network’s IP range is 192.168.1.X , the DSL-N55U IP has got to be configured differently other than 192.168.1.X (e.g DSL-N55U IP address is 192.168.2.1)
4. Next go to Internet connection-> If your ASDL settings are still there, remove it by clicking on the – at the far right corner and apply. If you do not have any ADSL settings, you should go to step 5.
   
5. You should see the following -> Make sure that Advanced settings -> WAN -> Automatic IP Is chosen and choose apply
   
6. Under Dual Wan tab, make sure that Primary wan is changed from DSL to Ethernet WAN, the LAN Port number is up to you .
   
7. That is all! Connect the DSL-N55U as an AP by the assied Ethernet WAN Port to your new network router. And it should work!
8. To remote into the DSL-N55U, check on your new router the IP address and if you can manually assign this IP so that every reboot or cold power startup it will take the same IP.

You are done if you just require internet surfing for devices connected on the Asus DSL-N55U AP. However if you require network services to be accessed on devices connected in the DSL-N55U subnet, you will need to do 2 more steps

1. On the DSL-N55U, turn off the firewall and appl
   
2. On your main new network router, you will need to route any traffic towards the DSL-N55U. Below assumes you are using another Asus Router. Assuming the new Asus Router is on subnet 192.168.1.x and you have setup the DSL-N55U’s AP Subnet as 192.168.2.x. The below example is to be done on the new Asus Router. You may also specify 1 IP address instead of the whole subnet.
   

I hope this article is useful and hopefully help you to put your Asus DSL-N55U Annex A to good use and not discard or throw it away. 🙂

Thoughts? Comments? Do share with us!