some pages load and some don’t

15 Jun

possible ipv6 problems

ipv6 uninstall

(after reassuring me that “ipv6 install” would be the
antidote if needed), which ran. Then I rebooted and lo! the
connection was happy. I thanked him, and asked why it
mattered, and he said, “To be honest, I don’t know; I just
know that this is a common problem.”

I finally found an explanation (via Google, of course):

“For example, this problem may occur when a Windows client
computer that is running IPv6 tries to access a Web site. The
Windows client will try to resolve the host name (for
example, www.example.com) on behalf of applications that
support both IPv6 and IPv4. To do this, the Windows client
will query for both “AAAA” records and “A” records, unless
the application specifies which protocol to use. If the DNS
server replies with an authoritative response that returns
NXDOMAIN or NAME_ERROR, Windows will return this response to
applications, such as Internet Explorer. Because of this, the
application will fail to resolve the host name and will be
unable to access the site. Note that Windows clients will
also cache this negative response. This prevents additional
queries for this name from succeeding until the client cache
is cleared.”

Using some of the keywords from this page finally found me a
Microsoft article,
http://www.microsoft.com/technet/prodtechnol/winxppro/plan/faqipv6.mspx#ECAAA ;
the answer is hidden under the question,
“Q. Why can’t applications, such as Microsoft Internet
Explorer, resolve domain names to IPv6 addresses for some DNS
servers?” (I had Googled for: “ipv6 uninstall” aaaa nxdomain
and then “Find” on the page didn’t find “nxdomain”, so I
found it in the page source…sigh).