Admins eHow SysAdmin Tips & Tricks

December 2, 2022

Redirect all DNS requests to local caching DNS server

Filed under: dns,linux — Tags: , , , , — admin @ 2:44 am

For caching DNS Server, I use PowerDNS recursor server. Install it first :

apt install pdns-recursor

By default it listens on and should work right after the installation, but for faster performance I want it to forward all queries to which is Google’s public DNS server. so change /etc/powerdns/recursor.conf and add the following line :

forward-zones-recurse= .=;

Restart the service after config change :

systemctl restart pdns-recursor.service

Now you can test it :

dig @

You should get a valid response.
Now lets redirect all DNS queries to our local server :

iptables -t nat -I OUTPUT -m owner --uid-owner pdns -j RETURN
iptables -t nat -I POSTROUTING -m owner --uid-owner pdns -j RETURN
iptables -t nat -A OUTPUT -p udp --dport 53 -j DNAT --to
iptables -t nat -A POSTROUTING -p udp --dport 53 -j SNAT --to-source

The first two iptables rules prevent a loop in redirecting pdns queries to outside world ( in our case).
Done. Easy 😉

May 12, 2009

How to install a caching only dns server using powerdns on debian lenny

Filed under: Debian,General — Tags: , , , — admin @ 3:50 pm

I just noted my caching bind9 dns server is using 306MB of my precious memory ! what the hell is it doing !? go to hell bind !

/etc/init.d/bind9 stop
apt-get remove bind9

so I decided to install another caching dns server , after some research I found PowerDNS. it uses MySQL for storing its zones , but hopefully its caching component doesnt need mysql , so great , lets go and install it.
My favourite OS is debian lenny , so I ran the following command :

apt-get install pdns-recursor

WOW , it was very simple ! it is already working on localhost , but I needed it to listen on all IPs on my box and accept queries from everyone 😀 I wanted to serve public :p so I went to /etc/powerdns and opened “recursor.conf” file and made the following changes :


and restarted the service by :

/etc/init.d/pdns-recursor restart

it’s done 😀 now it is working as a public caching name server.

Powered by WordPress