Hi alzhao, in the end openvpn works.

But I’m concerned about the messages in the system log. First of all there where no error messages in firmware 2.19 and I did not change the openvpn config. Second, I use the same openvpn config in the Openvpn app on an iPad, and there the log stays clear of error messages.

As I read in the readme of the firmware, version 2.255 contains openvpn version 2.4. My openvpn server is still 2.3. I will upgrade my openvpn server to version 2.4 to see if the route delete and route add still give error messages. Let you know in this post…