7 Replies
      Latest reply on Nov 9, 2018 3:58 AM by tech74
      tech74 Level 1 Level 1 (0 points)



        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