On Thu, Aug 29, 2019 at 03:13:45PM +0530, Naveen Kottapalli wrote: > My query was about the behavior we observed on a gateway where a pure v4 > subscriber (not dual-stack) has sent both A and AAAA query for the same > domain simultaneously. Just wanted to know why would a pure v4 subscriber > which cannot use the resolved AAAA domain addresses is trying to resolve > the v6 addresses of the domain.
As Viktor pointed out, when a process calls getaddrinfo() without hints, some libc implementations of getaddrinfo() don't consider what address families the system has configured as it doesn't matter at that library interface. For example, here is FreeBSD's getaddrinfo() implementation: https://github.com/freebsd/freebsd/blob/master/lib/libc/net/getaddrinfo.c#L2301 So, for example, FreeBSD's ping which uses gethostbyname2() with AF_INET will appear to lookup only the A record of a hostname being pinged, whereas FreeBSD's telnet which uses getaddrinfo() without hints (which gets converted internally to AF_UNSPEC) will appear to lookup both A and AAAA records. Also what Mark said applies that even if you think a subscriber has no v6 address/stack, they probably do. Mukund _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
