We can see in the device logs that vpn fails to launch, as iOS can not return the VPN head's IP address by resilving its FQDN.
I do not see any packets being sent out in the packet capture either.
Other services which do not rely on VPN work fine, and so does their DNS resolution using the same DNS servers.
The same vpn app works fine on iOS 9.3.2, and I am wondering if anyone ran into the issue.
This is a snippet of what I see in the iOS 10.2 device logs.
Any ideas or any pointers.. I am using getaddrinfo to get to the vpn head.
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: --------------
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: uDNS_CheckCurrentQuestion: host unreachable error for DNS server 4.2.2.2 for question [0000000107xxB8] xx.xx.com. (Addr)
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: GetServerForQuestion: 000000010700ACB8 DNS server (0000000105F0E760) 4.2.2.1:53 (Penalty Time Left 0) (Scope en0:0000000000000003:-1) found for name xx.xx.com. (Addr)
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: mDNSPlatformSendUDP -> sendto(17) failed to send packet on InterfaceID 0000000000000003 en0/4 to 4.2.2.1:53 skt 17 error -1 errno 65 (No route to host) 2517624299
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: -- ERROR -65569 Sending UDP DNS Query (flags 0100) RCODE: NoErr (0) RD ID: 5345 25 bytes from port 51337 to 4.2.2.1:53 --
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: 1 Questions
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: 0 xx.xx.com. Addr
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: 0 Answers
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: 0 Authorities
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: 0 Additionals
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: --------------
Jan 12 11:26:05 iPad-Trouble mDNSResponder[94] <Info>: uDNS_CheckCurrentQuestion: host unreachable error for DNS server 4.2.2.1 for question [000000010xxB8] xx.xx.xx (Addr)