Hi,
We have set up a NAT64 IPV6 network using mac mini running macOS Sierra. We have
a SIP ( VoIP) app which looks up DNS by using low level BSD sockets, so using connect on the
socket and sending low level queries.
We have a strange problem: an iPhone 5 (running iOS 10.2) and an iPad 4th gen ( running iOS 9.3 )
can connect to the DNS server address obtained from the MAC NAT64 network and get DNS responses.
However an iPhone 6S ( running iOS 10.2) and the exact same application code connects to the DNS server
address but no responses are received to a DNS query, just get timeouts.
We are not sure how to debug this because the DNS request goes via the MAC, any ideas would be most
appreciated.
Thanks