As a further follow-up to this. c-ares seems to suffer from the same
problem as the resip-ares fork in this regard (though the code is
If I look at the function "get_iphlpapi_dns_info" inside of ares_init.c,
I see that "GetNetworkParams" will be called (via a pointer to a
function). But, as this article suggests:
Most of the IP Helper functions were designed for IPv4, and do not
return IPv6 information. In fact, the only way to get statically
configured IPv6 DNS servers seems to be via the "GetAdaptersAddresses()"
If anyone could point me toward the person that owns this bit of code,
perhaps I can work with them to get this modified?
On 11-05-12 05:13 PM, David Stuart wrote:
> I've been chasing an issue from the resiprocate mailing list, which it
> turns out comes down to c-ares (or perhaps my use of it).
> I'll try to summarize the problem.
> I'm testing functionality of our product over IPv6 only networks; one of
> the issues we have is that we're having trouble sending DNS requests
> over IPv6 (note, parsing DNS results with IPv6 content is OK).
> My setup is like this:
> - Windows 7, with IPv4 stack turned off
> - IPv6 stack configured with static DNS server
> What I notice, is that c-ares does not find the statically configured
> IPv6 DNS server and therefore our application cannot send it a DNS
> request over IPv6.
> My feeling is that this is related somehow to the initialization of
> c-ares, and how it obtains the configuration from Windows. Can anyone
> help me to track down the problem? I'm currently using the latest
> (stable?) release downloaded directly from the website.
> Thanks in advance,
David Stuart, CounterPath
Email: dstuart (at) counterpath (dot) com
Phone: (613) 254-8886 x2234 Web: http://www.counterpath.com/
Address: 310 - 350 Terry Fox Drive, Kanata Ontario, K2K 2P5
Received on 2011-05-13