DuckDNS - unable to resolve

[superdx]

10.0.1.1 is the router's DNS. It would make sense that you may not be able to connect to it after connecting to VPN, but not before. Before is when OpenVPN Connect is trying to look up the hostname.

[superdx]

I think we've found the bug.

[superdx]

My Mac uses the same DNS 10.0.1.1 and Tunneblick works fine. Avoiding screenshot spam, Windows and Android are using identical DNS settings and they also connect fine.

[superdx]

The OpenVPN Connect app has an issue with how the server (host) DNS is resolved from wifi routers, at least consumer grade offerings.

For reference, Android and OSX devices on the same wifi networks do not have this problem. DNS resolution is immediate.

The test
Three routers: Airport Extreme (6th gen 2013), Linksys WRT54g, and a Lifetrons Air travel portable router.

I setup all 3 routers to use Google DNS 8.8.8.8 and 8.8.4.4 primary & secondary respectively. The connection to the internet is PPoE.

Airport Extreme DNS: 10.0.1.1
Linksys DNS: 196.168.16.1
Lifetrons Air DNS: 10.10.10.254

Result: Safari iOS, a Ping app and all other applications were able to use the internet perfectly.

However when OpenVPN tries to resolve DNS of the server (in this case, all my servers were using DuckDNS) using the router, it fails.

Current workaround
If a DNS server is typed directly into the iOS Network settings, bypassing the router, OpenVPN Connect can connect immediately without delay i.e. typing in 8.8.8.8 into the DNS server has an immediate effect. This was repeatable on all 3 routers.