@urbnsr In theory, this has nothing to do with ALG. You can try to continuously ping the WAN IP of site C on site A to see what the result is. In addition, can you provide information about your...

@RubyDesign I don't think you need to use so many routers, you can consider using their full set of SDN equipment. Purchase switch，EAP and OC200 to work with your existing ER605....

@Vedrit Do you mean that the controller cannot detect these two APs now ? If so, you can try to troubleshoot according to the FAQ on their official website to see if you can solve your problem....

@kasa_user Can your OC200 actually get the IP correctly? If it can get the IP, can you access it locally via IP ?

@caveboy 10.1.10.150---10.1.10.160 and your LAN IP are in the same network segment, which causes this problem. You can change the VPN IP Pool to 10.1.20.150--10.1.20.160 to fix the issue.

@MastaP Hey,do you mean that you have configured open vpn on the controller, and then after connecting to the vpn, devices on your external network cannot access your controller via IP?