GetAddrInfo cannot resolve ipv6.google.com (but nslookup can)

问题

i can trying to use GetAddrInfo to resolve ipv6.google.com:

wsaError = getaddrinfo("ipv6.google.com", null, null, ref addrInfo);

The returned socket error code is 11001 (No such host is known).

Note: The deprecated legacy function GetHostByName does not support IPv6. It has been replaced with GetAddrInfo.

The strange thing is that i can use nslookup and it can find the address just fine:

Question

SendRequest(), len 33
    HEADER:
        opcode = QUERY, id = 4, rcode = NOERROR
        header flags:  query, want recursion
        questions = 1,  answers = 0,  authority records = 0,  additional = 0

    QUESTIONS:
        ipv6.google.com, type = A, class = IN

Authoritative Answer

Got answer (106 bytes):
    HEADER:
        opcode = QUERY, id = 4, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 1,  authority records = 1,  additional = 0

    QUESTIONS:
        ipv6.google.com, type = A, class = IN
    ANSWERS:
    ->  ipv6.google.com
        type = CNAME, class = IN, dlen = 9
        canonical name = ipv6.l.google.com
        ttl = 21743 (6 hours 2 mins 23 secs)
    AUTHORITY RECORDS:
    ->  l.google.com
        type = SOA, class = IN, dlen = 38
        ttl = 30 (30 secs)
        primary name server = ns4.google.com
        responsible mail addr = dns-admin.google.com
        serial  = 1486713
        refresh = 900 (15 mins)
        retry   = 900 (15 mins)
        expire  = 1800 (30 mins)
        default TTL = 60 (1 min)

Non-authoritative question

SendRequest(), len 33
    HEADER:
        opcode = QUERY, id = 5, rcode = NOERROR
        header flags:  query, want recursion
        questions = 1,  answers = 0,  authority records = 0,  additional = 0

    QUESTIONS:
        ipv6.google.com, type = AAAA, class = IN

Non-authoritative answer

Got answer (82 bytes):
    HEADER:
        opcode = QUERY, id = 5, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 2,  authority records = 0,  additional = 0

    QUESTIONS:
        ipv6.google.com, type = AAAA, class = IN
    ANSWERS:
    ->  ipv6.google.com
        type = CNAME, class = IN, dlen = 9
        canonical name = ipv6.l.google.com
        ttl = 21743 (6 hours 2 mins 23 secs)
    ->  ipv6.l.google.com
        type = AAAA, class = IN, dlen = 16
        AAAA IPv6 address = 2607:f8b0:4009:801::1012
        ttl = 270 (4 mins 30 secs)

------------
Name:    ipv6.l.google.com
Address:  2607:f8b0:4009:801::1012
Aliases:  ipv6.google.com

What can cause nslookup to be able to resolve an address when GetAddrInfo cannot? And what can i do differently with GetAddrInfo so it works?

回答1:

Try passing AF_INET6 in pHints parameter to work with IPV6 addresses. This seems to be working for me:

struct addrinfo *result = NULL;
struct addrinfo hints;

ZeroMemory( &hints, sizeof(hints) );
hints.ai_family = AF_INET6;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;

dwRetval = getaddrinfo("ipv6.google.com", NULL, &hints, &result);
// check your dwRetval here ...

回答2:

I had similar issues, wasn't a problem with the code, but the operating system. The following command meant windows resolved the IPv6 addresses correctly instead of giving a WSANO_DATA error:

Netsh interface teredo set state enterpriseclient

Source:

http://netscantools.blogspot.co.uk/2011/06/ipv6-teredo-problems-and-solutions-on.html

来源：https://stackoverflow.com/questions/10767107/getaddrinfo-cannot-resolve-ipv6-google-com-but-nslookup-can