Configuring dnsmasq to query upstream nameservers for specific domains

> Dnsmasq has the ability to direct DNS queries for certain domains to specific upstream nameservers. This feature was added for use with VPNs but it is fully general. The scenario is this: you have a standard internet connection via an ISP, and dnsmasq is configured to forward queries to the ISP’s nameservers, then you make a VPN connection into your companies network, giving access to hosts inside the company firewall. You have access, but since many of the internal hosts aren’t visible on the public internet, your company doesn’t publish them to the public DNS and you can’t get their IP address from the ISP nameservers. The solution is to use the companies nameserver for private domains within the company, and dnsmasq allows this. Assuming that internal company machines are all in the domain internal.myco.com and the companies nameserver is at 192.168.10.1 then the option server=/internal.myco.com/192.168.10.1 will direct all queries in the internal domain to the correct nameserver. You can specify more than one domain in each server option. If there is more than one nameserver just include as many server options as is needed to specify them all.

Configuring Dnsmasq.