Spent way too long troubleshooting an issue where OpenVPN Connect, on iOS in this case, was connecting to the server successfully, receiving both an IPv6 address and gateway assignment, and the instruction to redirect all IPv6 traffic to the tunnel interface since this server is set to not allow split tunnel. Well, IPv6 was not actually working. I installed the Hurricane Electric app and was able to confirm the v6 routing table looked fine. I could not ping the v6 gateway…
OpenVPN Connect debug log showed these odd items that my other clients didn’t:
2020-03-12 13:55:22 Peer Info: IV_IPv6=0
2020-03-12 13:55:33 NIP: blocking all IPv6 traffic
2020-03-12 13:55:33 OPTIONS: 16 [block-ipv6]
So of course all of this seemed to suggest the server was instructing my client to block IPv6. Nope, just my stupidity; the client software had IPv4-only set in its settings… a quick reconfigure to no preference resolved the issue.