AC68U - Unable to do WAN USB Tethering with Android phone on AT&T

[galfert]

Hello,
I'm unable to figure out how to properly configure my RT-AC68U for WAN via my Android phone on AT&T.

Details:
Phone: Samsung Galaxy S8 (AT&T branded)
ISP Provider: AT&T cellular
Mobile plan: Yes it allows for hotspot WiFI tethering and USB tethering (tested directly on laptop via both WiFi hotspot and USB tethering)
Router: RT-AC68U
Firmware: Asuswrt-Merlin 384.19 (factory reset and erased all settings) using no mods - using default configuration, nothing has been changed from factory reset.
Tested Enviroment: No other networking equipment other than a Windows laptop connect to router LAN and phone connected to USB port with known working USB cable, nothing else on LAN.
Cellular reception: Good strong full bars and the phone works as USB tethering if I plug it in directly into laptop.

I've tried researching this issue and I've tried everything I could think of and all that I've read. Tried both the USB 2.0 and 3.0 ports. Tried leaving MTU set to 0 and also tried 1484. Tried both with dual WAN and without dual WAN. Tried setting as primary and as secondary for USB Android phone. Tried both Extend TTL and Spoof LAN TTL separately (one at a time) and combined (both set to Yes). Tried with and without network detection when using dual WAN. When testing with dual WAN the mode is set to Fail over. Nothing no Ethernet plugged into WAN port. There is no other Internet. The only thing I can think of is that maybe this only works if there is some other service on Ethernet WAN. When phone is USB connected and USB tethering is turned on the router status for WAN keeps saying that the connection type is USB Modem instead of Android phone...even though it is set for Android phone and not USB Modem.

I don't know what else to try. Please let me know if you need any other details.

 

[El Indalo]

The only thing I can think of is that maybe this only works if there is some other service on Ethernet WAN.

This is not the problem as I use a (different brand of) Android phone with no other service on Ethernet WAN.

On the ASUS web site there is a list of compatible Android phones, check this out for your model. Search for mobile tethering support.

https://icr-am.asus.com/webchat/icr.html?rootTreeId=AM.US.EN-US&treeId=AM.US.EN-US.Network&tenantId=EN-US

 

[galfert]

Thank you for the tip on looking up supported phones. Unfortunately the Asus website link for the compatibility list produces a 404 not found error

https://event.asus.com/2013/nw/mobile_tethering_support/?_ga=1.23114362.1717103240.1398267030

 

[galfert]

This other list that I found only lists cellular modems and not phones:

Networks 3G4G Support

 

[L&LD]

@galfert does this list show up for you?

https://icr-am.asus.com/webchat/icr.html?rootTreeId=AM.US.EN-US&treeId=AM.US.EN-US.Network&tenantId=EN-US

Edit: Sorry, I see it's the same link as @El Indalo posted above.

When on the website, can you click the number '19' link in the left-hand column and then the '1' link?

Edit 2: Gaaaa! Sorry, I need a coffee first!

 

[galfert]

Yes it shows up...

 

[galfert]

The problem is when I get to #3 depicted in my screenshot doesn't produce a list of supported phone devices.

 

[octopus]

You have to allow popup screen.

 

[galfert]

No there is no pop-up suppression. It opens a new tab just fine and just shows this (I thought it might be Pi-hole issue so I disabled and still doesn't work.):

 

[galfert]

If anyone else can open that link can you copy and past the contents to see the list of supported phones?

 

[octopus]

No there is no pop-up suppression. It opens a new tab just fine and just shows this (I thought it might be Pi-hole issue so I disabled and still doesn't work.):

View attachment 28552

 

[galfert]

Octopus,
This page link below (which I can see just fine) offers no list of supported phones:

https://www.asus.com/us/support/FAQ/1030649/

[Troubleshooting] Cannot use smart phone to share Internet through the ASUS router | Official Support | ASUS USA

 

[galfert]

@galfert does this list show up for you?

https://icr-am.asus.com/webchat/icr.html?rootTreeId=AM.US.EN-US&treeId=AM.US.EN-US.Network&tenantId=EN-US

Edit: Sorry, I see it's the same link as @El Indalo posted above.

When on the website, can you click the number '19' link in the left-hand column and then the '1' link?

Edit 2: Gaaaa! Sorry, I need a coffee first!

Why would I click on '1' link? That is for 3G/4G adapter compatibility. We are trying to troubleshoot an Android phone not a USB modem which would mean '3' link. I'm trying to get list of supported Android phones and I can't.

 

[L&LD]

I already apologized.

I needed more coffee so late in my day.

 

[galfert]

I already apologized.

I needed more coffee so late in my day.

Oh okay.. my bad misread your post. np.

 

[galfert]

It just seems to me that one of the most popular and flagship phones of its time that is only about 2 years old would not be supported (Samsung Galaxy S8). Works just fine when plugging into Windows PC via USB. If Asus has this "Android Phone" USB tethering support then just what phones would that be referring to?

Has anyone gotten USB Android Phone tethering to work? If yes what phone are you using? And again if anyone can get the official list from Asus that would be great because the link doesn't work.

 

[ColinTaylor]

I'm using John's firmware on my RT-AC68U rather than Merlin's (John recently back ported Merlin's Android support) and it works fine with my Samsung Galaxy S6. It was rather flaky to get going and I'm not sure it would have worked if there wasn't also something connected to the WAN port.

 

[galfert]

Thank you for the tip on John's firmware. I might give it a go.

The other solution I found is to use two routers. I have the main router and then set a secondary router as a wireless bridge. The wireless bridge gets connected via Ethernet to the main router into what I configured as a 2nd WAN port on the main router. Then on the phone I turn on the WiFi hotspot and the 2nd router acting as a WiFi bridge uses the phone as an Internet source.

Main Router 2nd WAN Ethernet ---> Other router configured as WiFi Bridge ---> phone with WiFi Hotspot turned on

It would also work with the Main Router primary WAN....but I really needed this as a fail over.

 

[El Indalo]

Sorry for any confusion I caused by posting what turns out to be an outdated and non-working link.

 

[heysoundude]

This person seems to have it in hand:

If you're more comfy with command line: