OpenVPN only works by disabling NAT (or using TCP)

OpenVPN only works by disabling NAT (or using TCP)

OpenVPN only works by disabling NAT (or using TCP)
OpenVPN only works by disabling NAT (or using TCP)
2024-08-13 15:42:36 - last edited 2024-08-14 15:30:08
Tags: #VPN #OpenVPN
Model: Archer AXE75  
Hardware Version: V1
Firmware Version: 1.2.1 Build 20240607

Hello,

 

I'm setting up OpenVPN on my Archer AXE75 router, but I'm facing some issues.

 

The connection only works if I either:

 

  • Use TCP instead of UDP in the OpenVPN server configuration,

  • OR

  • Disable NAT entirely in the Network -> Internet settings (UDP OpenVPN works in this case, but it causes my local devices to lose internet connectivity).

 

Since I can connect to the VPN from my mobile 4G connection when using TCP (or by disabling NAT), I've narrowed the problem down to the combination of NAT and UDP.

I've tried port triggering in the NAT settings, but it didn't work.

 

Does anyone have any suggestions?

  0      
  0      
#1
Options
1 Accepted Solution
Re:OpenVPN only works by disabling NAT (or using TCP)-Solution
2024-08-14 09:36:53 - last edited 2024-08-14 15:30:08

  @AlexMJr 

Hi

 

It appears that you are accessing the VPN server from the LAN side. In this scenario, only TCP connections may function properly.

To address this issue, it is advised to utilize mobile data or connect to other networks.

Recommended Solution
  0  
  0  
#2
Options
2 Reply
Re:OpenVPN only works by disabling NAT (or using TCP)-Solution
2024-08-14 09:36:53 - last edited 2024-08-14 15:30:08

  @AlexMJr 

Hi

 

It appears that you are accessing the VPN server from the LAN side. In this scenario, only TCP connections may function properly.

To address this issue, it is advised to utilize mobile data or connect to other networks.

Recommended Solution
  0  
  0  
#2
Options
Re:OpenVPN only works by disabling NAT (or using TCP)
2024-08-14 15:29:30 - last edited 2024-08-14 15:31:32

@Joseph-TP 

Thanks for the reply!

 

You got me thinking, and you're right! I was indeed connected to the LAN.

 

I activated my mobile phone's hotspot to connect my laptop to the 4G network, but I forgot to disconnect the phone from my WiFi router (which provides the VPN connection). So the hotspot was serving my own WiFi to me instead of mobile data.

Tip for anyone reading this: remember to disconnect from your router's WiFi when testing your VPN connection.

 

Everything's working great now! Problem solved.

 

Thanks!

  0  
  0  
#3
Options