TX-AX6000 works as VPN client but not VPN server (both OpenVPN and Wireguard)

[argodgod]

Hi everyone, I have been reading posts here for quite some time about setting up VPN at Asus routers. I want to set up VPN so that my friend and I can link our household network together to share the same IP address. Both of us are not that good in networking related stuff, so we figured out the easiest way is to make use of the VPN built-in Asus routers for a relatively easier setup and connection action.

I bought a TX-AX6000 (mainland China version) first and tried the VPN connection with my other friends (one with AC68U or AC86U and another with AX88U). My router works perfectly fine as VPN client (both OpenVPN and Wireguard) connecting to their respective VPN servers on routers. However, when I tried acting as the server and let them connect as clients, it didn't work. I set up DDNS because my ISP does not provide static IP. My friends tried connecting as clients with their router and their smartphones, saw something like "waiting server" or "waiting connection". We all configured the server by default setting (actually same setting, we printsreen and checked), set up and used username and pw for OpenVPN, and I'm also sure that I didn't turn on both server and client at the same time.

May I have any suggestion what might have caused this issue? My apology in advance if I am missing some essential information for the analysis.

Thank you so much.

 

[L&LD]

I don't recognize that model. Do you have a link?

 

[argodgod]

I don't recognize that model. Do you have a link?

https://www.asus.com.cn/networking-iot-servers/wifi-routers/asus-gaming-routers/tx-ax6000/techspec/

It's a Mainland Chinese version so I doubt whether they have the info in English. Heard that its the same spec as tuf ax 6000 but not sure.

 

[L&LD]

Good hardware 'specs', but not RMerlin-supported.

Can you get the RT-AX88U Pro instead?

Or, wait for updated firmware that fixes these issues?

Checking...
did you flash the latest firmware available for it and then perform a full reset to factory defaults?

Did you import any old backup config file?

Do you have any USB drives connected?

 

[argodgod]

Good hardware 'specs', but not RMerlin-supported.

Can you get the RT-AX88U Pro instead?

Or, wait for updated firmware that fixes these issues?

Checking...
did you flash the latest firmware available for it and then perform a full reset to factory defaults?

Did you import any old backup config file?

Do you have any USB drives connected?

Thanks for your suggestion. I update the firmware by the app once I set it up for the first time. Didnt realize I need to reset it even I am not using other firmware. Will try that later today.

I didnt import any old config nor connect any usb drive.

 

[ColinTaylor]

However, when I tried acting as the server and let them connect as clients, it didn't work. I set up DDNS because my ISP does not provide static IP. My friends tried connecting as clients with their router and their smartphones, saw something like "waiting server" or "waiting connection".

Confirm that your router has a public WAN IP address shown on the Network Map page.

 

[TheLostSwede]

A static IP address isn't required, but have you enabled DDNS, it makes life a lot easier when using with VPN.
Does Instant Guard work if you enable it? It's Asus' own easy to use VPN service and a quick way to make sure everything works.
I find WireGuard is easier to get up and running in general and have been using it for well over a year now.

 

[Tech9]

Public WAN IP is required.

 

[TheLostSwede]

Public WAN IP is required.

Yeah, that too. Just realised I'm behind a CGNAT as I was trying to set up VPN on my GT-AX6000. At least my ISP allows me to apply for a public IP address, so in my case it's an easy problem to solve.

 

[Tech9]

You can do IPv6, I believe it is supported in Asuswrt for VPN Server. Sorry, don't have the Asus router running at the moment to verify.

 

[argodgod]

Thanks all for your advices. Regarding the public WAN IP, I should have one, I see and IP on the front page of the router setting.

While I was waiting for any insights yesterday, I decided to pass my router to one of my friends (whose AC86U works well on VPN) and you know what, my router works perfectly. We use the same ISP and he only uses the default setting for the VPN, and my router has no issue at all. If it's not about the router, then it must be the modem or the fibre or the ISP setting, so I called the ISP customer service last night. They said they will restart my connection for a new dynamic IP. After that I used and AC5300 (from friend, also for testing purpose before the new router purchase, also didn't work) and finally it worked as the openvpn server.

I am waiting my new router back and try again. I should have tried calling the ISP before I brought my question here. Will update you all later. Thanks again for all your help.

 

[TheLostSwede]

Thanks all for your advices. Regarding the public WAN IP, I should have one, I see and IP on the front page of the router setting.

Does it start with100.x.x.x ? Then it's behind a CGNAT.

 

[argodgod]

Problem solved, and it's due to the ISP issue. My router worked well at my friend's home who has been using OpenVPN on AC86U, so I called the ISP and checked because the only possible issue would either be the modem or the connection with the ISP. Their CS said they would reconnect me and after waiting for a few minutes and restarting my modem. It works perfectly now.

My another friend encountered exactly the same situation, called the ISP and problem resolved. Looks like they applied different setting on different users

Apology for the question caused by stupid arrangement of the ISP. Thanks all again.