OpenVPN Half Working From Client Site
I've had OpenVPN set up and working on my SG-2440 for quite some time (2.2.x and now 2.3.1), and it's been working great. It's setup for remote access, and I use it to connect back to my LAN from various client sites when I travel around. At one client site in particular, when I connect to my server, OpenVPN connects and I can go online and use IPv6, but anything that's IPv4 doesn't work. This is true for IPv6 enabled Internet sites such as Google. This only happens at this particular client's guest network. Their guest network is only IPv4 with no IPv6, so I know for sure that the IPv6 traffic is going though the tunnel, but IPv4 is broken some how. It's really strange. I thought that the OpenVPN traffic is all encrypted over the IPv4 connection back to my pfSense server. How can just the IPv4 over the tunnel be broken? And, why only at this customer site? Is it something I have possibly misconfigured?
Anyone have any clues as to why this is happening? Or, how it could be happening?