On Mon, 23 Aug 2010, Tom H wrote: > To: CentOS mailing list <centos at centos.org> > From: Tom H <tomh0665 at gmail.com> > Subject: Re: [CentOS] Slow domain resolution problem > > On Mon, Aug 23, 2010 at 9:48 AM, Giles Coochey <giles at coochey.net> wrote: >> >> The problems can sometimes be caused by not having reverse-DNS records for >> your hosts. Can you resolve to names (any name) from an IP address? >> e.g. nslookup 10.2.9.2? > > If this is a reverse-lookup problem and you can't have a > reverse-lookup zone (I worked at a company where the Windows admins > refused to create one when we asked them to do so!), you can add > "[NOTFOUND=return]" to the hosts line in nsswitch.conf after "dns" > otherwise your dns server will forward the query out to the net > (assuming that your egress rules allow it to do so) and an answer will > be returned by the some servers set up for this purpose on the net - > called blackhole-something, IIRC. > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos Not sure if it is RDNS. I had similar issues on Fedora, and for me it was to do with IP6. Konqueror web browser took ages to load a page. IIRC Firefox handled it OK. Try Googling for 'uninstalling ipv6 linux' That solved the Konqueror DNS problem for me. Yours could be a different issue. Here's the results of going to the ShieldsUp page at https://www.grc.com/x/ne.dll?bh0bkyd2 Your Internet connection has no Reverse DNS Many Internet connection IP addresses are associated with a DNS machine name. (But yours is not.) The presence of "Reverse DNS", which allows the machine name to be retrieved from the IP address, can represent a privacy and possible security concern for Internet consumers since it may uniquely and persistently identify your Internet account — and therefore you — and may disclose other information, such as your geographic location. When present, reverse DNS is supported by Internet service providers. But no such lookups are possible with your current Internet connection address (81.168.74.150). That's generally a good thing. Another thing is how many DNS IP addresses do you have in /etc/resolv.conf? I only had one DNS IP address thanks to NetworkManager on F12. And that DNS host went down at my ISP end! I use four IP addresses now in my reslov.conf file. Kind Regards, Keith Roberts ----------------------------------------------------------------- Websites: http://www.php-debuggers.net http://www.karsites.net http://www.raised-from-the-dead.org.uk All email addresses are challenge-response protected with TMDA [http://tmda.net] -----------------------------------------------------------------