Problem with slow httplib connections on Windows (and maybe other platforms)

[Christoph Zwerschke]

rdmurray at bitdance.com schrieb:
> Quoth Christoph Zwerschke <cito at online.de>:
>>    With Py 2.3 (without IPv6 support) this is only the IPv4 address,
>>    but with Py 2.4-2.6 the order is (on my Win XP host) the IPv6 address
>>    first, then the IPv4 address. Since the IPv6 address is checked first,
>>    this gives a timeout and causes the slow connect() call. The order by
>>    which getaddrinfo returns IPv4/v6 under Linux seems to vary depending
>>    on the glibc version, so it may be a problem on other platforms, too.
> 
> Based on something I read in another thread, this appears to be a problem
> only under Windows.  Everybody else implemented the TCP/IP stack according
> to spec, and the IPV6 connect attempt times out immediately, producing
> no slowdown.
> 
> Microsoft, however....

The order in which getaddrinfo returns IPv4 and IPv6 is probably not 
written in the specs (Posix 1003.1g and RFC 2553). The fact that Windows 
returns IPv6 addresses first is not wrong in itself.

For this discussion, see also
http://www.ops.ietf.org/lists/v6ops/v6ops.2002/msg00869.html
https://bugzilla.redhat.com/show_bug.cgi?id=190495

But yes, I also wonder why the connect to the IPv6 loopback address does 
not time out more quickly on Windows.

-- Christoph