How to change dnsmasq port?

Question

I am using port 53 for my vpn, and I need to use port 53. I changed the port of dnsmasq, connected openVPN, and now request are unable to resolve errors.

sudo dnsmasq -p 5642

. Is there a way to change the port of dnsmasq w/o conflicts/errors?

Answer 1

No. Every piece of DNS requester software expects to find the DNS service on port 53 of the nameserver. If it is not there then DNS will not work.

$ grep '\s53/' /etc/services 
domain          53/tcp                          # name-domain server
domain          53/udp

Answer 2

Actually some unix distros allow you to specify the port for DNS in the /etc/resolv.conf nameservers entry but unfortunately Ubuntu isn't one of them. If it were possible you would specify the DNS port in /etc/network/interfaces along with the IP address of the nameserver — presumably a loopback address in your case.

There is an enhancement logged: Please allow specification of port in resolv.conf

My guess is that you will have move the port that your VPN is using. However, there is probably a good reason why the VPN is listening on the DNS port. You might want to check it out before trying to change it; you might be trying to do something that it already does for you.