Peter Haight wrote: > >www.vanguard.com has a broken DNS implementation. > >Find out the zone administrator via SOA record or whois and complain. > >RFC requires the behavour you saw with google. > > Ok. The thing is that there are a lot of these sites. Watching the log on > the other side of my DNS server it looks like it is sending requests to > vanguard's dns server, but not getting any replies. Is there some way I can > lower the timeout for IPV6 DNS lookups or maybe disable them? Or is there > some change I can make to mozilla to minimize the impact of sites like > these? > > Hmm. Looking at the FreeBSD resolver code, it doesn't look like there is > some convenient way to do this. Maybe something like, try the AAAA lookup, > but if we don't get any reply in a short timeout, try an A lookup. If we get > a reply to that, then log the site as probably not conforming to the RFC.
The best answer is to do what Bernd said, and get the server fixed, since it's an RFC non-conforming server. If you can't do that, the best thing to do on the client side is to do a concurrent IPv6 and IPv4 lookup, and then if the IPv6 times out, take the IPv4 answer. Basically, this means you will have to live with the IPv6 timeout period, no matter what, but at least it won't stack on top of an IPv4 timeout. The best concurrent resolver library is the one that ships with the current version of bind. FreeBSD's resolver library is older than this, and not concurrent, because it's integrated into libc, and not in a seperate libresolv, which makes it hard to upgrade. For an individual application, like the Mozilla you said you were using in your first posting, you can link the bond supplied libresolv before libc, and that will get the new resolver library before the libc version (you will also need to point the compiler at the newer header files, via "-I<path>", to get the newer behaviour). I'm not sure that Mozilla is aware of the asyncronois interface, if they are in the compilation scope; I'd be surprised if it knew about IPv6 but not about the async interfaces. Good luck. -- Terry To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
