View Full Version : [ubuntu] Multiple DNS servers

September 8th, 2010, 05:26 PM
Because of latency problems with my ISP's DNS servers, I switched to using OpenDNS by inserting a prepend... line in /etc/dhcp3/dhclient.conf. (I am also using dnsmasq to cache results locally.) But I find that often I get considerable latency with OpenDNS as well. Is there any way, in dhclient.conf or elsewhere, to send each query to two servers simultaneously (one OpenDNS and the other my ISP) and use whichever result comes back fastest?


September 10th, 2010, 03:12 AM
Hi there,

The only way to perform two queries in parallel like that is to set up your own DNS server. Pdns, for example, has the ability to perform parallel queries, and is specifically designed with caching in mind. The next best option would be to periodically query your ISP & OpenDNS serially, measure their response times, and rewrite your system's DNS configuration accordingly. That would be quite a bit simpler (ie just a quick script), but not nearly as effective.

September 10th, 2010, 04:35 AM
I've had pretty good luck setting up systems to use google's dns ( and

September 10th, 2010, 10:15 PM
Many thanks for the ideas. As a matter of principle, I do not use Google's services unless I absolutely have to. But pdns looks interesting; I will have to see how involved the setup is. --treacl