After troubleshooting OpenVPN issues for the past few days; I figured I'd share my results to save somebody else the headache in the future. Here's what I found...
I recently installed a Nighthawk R7350 as my main home router. I updated the firmware to V1.2.0.92_1.0.1, which was the latest version at the time. One of the features I wanted to use was OpenVPN to connect my mobile phone to my home network while I'm away from home. However, while I could connect to OpenVPN using the instructions provided online, I could not access any home devices or the Internet.
After LOTS of troubleshooting I noticed that the router seems to hand out 192.168.2.X IP addresses to VPN clients. The problem was that I changed my router's LAN settings to also use the 192.168.2.0/24 address space. So, when my iPhone connected to OpenVPN in TUN (routing) mode; the router was trying to route between two networks with the same address space. Or at least this is what appeared to be happening. And there doesn't seem to be a way to change the OpenVPN server configurations to mitigate this.
After changing my router's LAN configuration to use the 192.168.1.0/24 address space everything seemed to work. I'm not sure if this is a bug or if I missed a warning message somewhere in the documentation that states you can't use the 192.168.2.0/24 address space for the LAN if you plan to use OpenVPN. In either case; hopefully this post will help somebody else out there that runs into the same problem.
After LOTS of troubleshooting I noticed that the router seems to hand out 192.168.2.X IP addresses to VPN clients. The problem was that I changed my router's LAN settings to also use the 192.168.2.0/24 address space.
FWIW, I use 10.0.0.x addresses myself, and have no issue with OpenVPN. That's not to say your info is wrong, just that it does work ok with the subnet I use.
