MacOS X

Custom DNS Resolver

Although MacOS X has /etc/resolve.conf, it is actually not used. In order to add a custom resolver for a network (eg. intranet), you need to create a file with the same structure as resolve.conf under /etc/resolver/. The name is not important.

#/etc/resolver/intranet
search intranet
nameserver 172.16.0.1

To flush the DNS cache, run sudo killall -HUP mDNSResponder and you can check the new resolvers with scutil –dns.