When a dns lookup is made for a host that returns a large number of results for A (over 28 records in my test) and a finite number for AAAA, getaddrinfo ends up returning only the AAAA records. I have posted a patch on libc-alpha to fix this: http://sourceware.org/ml/libc-alpha/2012-02/msg00502.html An example DNS zone file that should trigger this problem: $TTL 86400 ; 24 hours could have been written as 24h or 1d $ORIGIN foo.net. @ 1D IN SOA ns1.foo.net. hostmaster.foo.net. ( 2002022401 ; serial 3H ; refresh 15 ; retry 1w ; expire 3h ; minimum ) IN NS ns1.foo.net. ; in the domain ; server host definitions ns1 IN A 192.168.0.1 ;name server definition ; non server domain hosts ad IN A 1.0.0.1 ad IN A 1.0.0.2 ad IN A 1.0.0.3 ad IN A 1.0.0.4 ad IN A 1.0.0.5 ad IN A 1.0.0.6 ad IN A 1.0.0.7 ad IN A 1.0.0.8 ad IN A 1.0.0.9 ad IN A 1.0.1.1 ad IN A 1.0.1.2 ad IN A 1.0.1.3 ad IN A 1.0.1.4 ad IN A 1.0.1.5 ad IN A 1.0.1.6 ad IN A 1.0.1.7 ad IN A 1.0.1.8 ad IN A 1.0.1.9 ad IN A 1.0.2.1 ad IN A 1.0.2.2 ad IN A 1.0.2.3 ad IN A 1.0.2.4 ad IN A 1.0.2.5 ad IN A 1.0.2.6 ad IN A 1.0.2.7 ad IN A 1.0.2.8 ad IN A 1.0.2.9 ad IN A 1.0.3.1 ad IN AAAA 2002:2003:dead::beef:f00d A simple lookup program returns just the IPv6 address and not the ipv4 addresses: #include <stdio.h> #include <stdlib.h> #include <netdb.h> #include <netinet/in.h> #include <sys/socket.h> int main(void) { struct addrinfo *result; struct addrinfo *res; int error; const char *domain = "ad.foo.net"; error = getaddrinfo(domain, NULL, NULL, &result); if (error != 0) { fprintf(stderr, "error in getaddrinfo: %s\n", gaistrerror(error)); return 1; } /* print the domain name */ printf("%s:\n", domain); /* loop over all returned results and print the addresses */ for (res = result; res != NULL; res = res->ainext) { void *addr; char address[64] = ""; if (res->aifamily == AFINET) { addr = &((struct sockaddrin *)(res->aiaddr))->sinaddr; } else if (res->aifamily == AFINET6) { addr = &((struct sockaddrin6 *)(res->aiaddr))->sin6addr; } inetntop(res->aiaddr->safamily, addr, address, 64); printf(" %s\n", address); } freeaddrinfo(result); return EXITSUCCESS; } $ ./a.out ad.foo.net: 2002:2003:dead::beef:f00d 2002:2003:dead::beef:f00d 2002:2003:dead::beef:f00d
Fixed in master with 86ae07a8c9e8e26806f7b8dedf57e7b14a308c69.