Comments on: Setup a persistent local DNS cache on Ubuntu Jaunty with pdnsd and OpenDNS

By: 2010 in review « Jon Thysell

2010 in review « Jon Thysell — Sun, 02 Jan 2011 18:39:26 +0000

[...] Setup a persistent local DNS cache on Ubuntu Jaunty with pdnsd and OpenDNS September 2009 6 comments 3 [...]

By: Will

Will — Mon, 05 Apr 2010 05:23:51 +0000

I tried this and works fine in karmic even on an IP renewal. One thing I did add since I done this almost similar setup using bind9 as local caching is to edit

/etc/dhcp3/dhclient.conf

and uncomment this line.

prepend domain-name-servers 127.0.0.1;

By: Jon

Jon — Thu, 07 Jan 2010 15:01:08 +0000

It’s the NetworkManager. Every time Gnome asks for the IP, it overwrites the text file. Won’t matter if you tell the router to use the same address.

I currently don’t have it set up any more (fresh install of Karmic Koala), because I’ve found that my router already caches DNS requests, so I just set my router to use OpenDNS and let my machines point to it.

By: John Tindle

John Tindle — Thu, 07 Jan 2010 13:32:20 +0000

Hi,

This is way too useful to me! How do I get round the impermenance please? Is it the very act of DHCP renewal that causes the problem or a change in IP in a new lease? For me if it is just a problem of the DHCP lease carrying a new IP address, then I will tell the router to lock down my IP address to my MAC.

Anyway, thanks for sharing this solution, my ISP has decided to do DNS rerouting for commercial purposes and the performance hit is killing me.

John

By: Jon

Jon — Mon, 12 Oct 2009 15:16:41 +0000

@Henry H: Yeah, I've since noticed that. It happens whenever the NetworkManager refreshes the ip address from dhcp. I'm on a desktop and go weeks between dhcp updates. I'm trying to figure out a persistent solution that minimizes the need to edit config files by hand.

By: Henry H

Henry H — Mon, 12 Oct 2009 14:35:36 +0000

It doesn’t appear to be permanent. The symlink gets replaced with a file at some point in time and reverts back to the connection-provided DNS server instead of the local cache.

I get the following error when running ‘sudo resolvconf -u’

resolvconf: Error: /etc/resolv.conf must be a symlink

By: Ant Lees

Ant Lees — Sun, 04 Oct 2009 02:44:50 +0000

That worked a treat. Thanks for sharing.