[EXTERNAL] dig and host don't work in IPv6

[Lee]

On 7/29/23, Andrew Schulman via Cygwin <cygwin@cygwin.com> wrote:
>> Sorry...  Did you try using the -d option to see what DNS servers these
>> commands try to actually connect to (and time out, eventually).
>
> No help unfortunately.
>
> $ host -d6 cygwin.com
> Trying "cygwin.com"
> ;; connection timed out; no servers could be reached

Have you tried the windows version of bind from isc.org?

I don't remember when ISC dropped (will drop?) support for windows,
but I've been using dig from the bind9.16.41 package for a while.  Not
that I use it all that much, but it works for me.. or at  least dig
does.  named on windows has something funky going on that I never
figured out, so I'm running named on Debian.

Get it here
https://ftp.isc.org/isc/bind9/9.16.41/BIND9.16.41.x64.zip

unzip and put that directory in your path
$ which dig
/cygdrive/c/Temp/BIND/dig

and have fun!
$ dig @2600:x:x:x::x:x www.google.com aaaa +short
2607:f8b0:4004:c09::67
2607:f8b0:4004:c09::69
2607:f8b0:4004:c09::93
2607:f8b0:4004:c09::63

Lee@i3668 ~
$ dig @2600:x:x:x::x:x www.google.com a +short
172.253.122.147
172.253.122.103
172.253.122.99
172.253.122.104
172.253.122.105
172.253.122.106

ipv6 address hidden to protect the guilty :)

... hrmmm ... I just tried your "host -d6 cygwin.com" and got
$ host -d6 cygwin.com
Trying "cygwin.com"
;; connection timed out; no servers could be reached

Do you have a firewall blocking outbound udp/tcp to port 53?  I do,
which is most probably why I get the timeout.  But this works:
$ host cygwin.com 2600:x:x:x::x:x
Using domain server:
Name: 2600:x:x:202::x:x
Address: 2600:x:x:202::x:x#53
Aliases:

cygwin.com has address 8.43.85.97
cygwin.com mail is handled by 10 sourceware.org.


Maybe try using whatever dig you already have installed and do
  ipconfig /all | grep "DNS Server"
and then
  dig @<my dns server address> cygwin.com

Regards,
Lee


>
>> (strace can help as well, I think.)
>
> Posted at https://pastebin.com/XWwxJ41b. I'm not able to make much sense of
> it,
> except that on line 1339, I waited almost 5 seconds for sendmsg:
>
> 4964291 6958349 [isc-worker0000] host 20999 cygwin_sendmsg: 28 =
> sendmsg(20,
> 0x7FFDFC830, 0x0)
>
> Thanks for taking a look. I'm looking at other options in resolv.conf, but
> haven't found anything useful.
>
> I can't find any documention of the osquery option. This answer[1] says
> "res_init() uses the Windows resolver if either /etc/resolv.conf does not
> exist,
> or /etc/resolv.conf contains options osquery." Doesn't help in this case
> though.
>
> Andrew
>
> [1]
> https://stackoverflow.com/questions/10523828/how-does-gcc-cygwin-get-the-dns-server
>
>
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