Ubuntu manage its network connections through Network Manager.
Network Manager manages:
- DHCP client
- DNS client (resolv.conf which refers to dnsmasq local cache service)
- Interface connections (instead of ifup/ifdown)
When you try to read resolv.conf file you will always see that it directed to 127.0.0.1#53 – this is dnsmasq service.
when Network Manager runs, it also run dnsmasq by default (you can see that in “ps aux | grep dnsmasq”.
To enable/disable dnsmasq cache change the file /etc/NetworkManager/NetworkManager.conf
to see which are your dns servers run nm-tool.
the dnsmasq service gets dns servers from dhcp.
if you want to create custom configuration file you can read the properties in “man dnsmasq”
the package is called dnsmasq-base.