Set up Dnsmasq on Mac OS X

setup-dnsmasq-macosx.sh-session

$ # Install dnsmasq
$ brew update && brew install dnsmasq

$ # Edit dnsmasq config, paste contents
$ mkdir -p /usr/local/etc && vim /usr/local/etc/dnsmasq.conf

$ # Start dnsmasq (it will restart at startup)
$ sudo brew services start dnsmasq
==> Successfully started `dnsmasq` (label: homebrew.mxcl.dnsmasq)

$ # Verify dnsmasq is running
$ ps -ef | grep dnsmasq
   -2    50     1   0  2:28PM ??         0:00.11 /usr/local/opt/dnsmasq/sbin/dnsmasq --keep-in-foreground -C /usr/local/etc/dnsmasq.conf

$ # Find your current DNS settings
$ scutil --dns
DNS configuration (for scoped queries)

resolver #1
  nameserver[0] : x.x.x.x
  nameserver[1] : y.y.y.y
  nameserver[2] : z.z.z.z
  if_index : 4 (en0)
  flags    : Scoped, Request A records, Request AAAA records
Reachable, Local Address

$ # (Optional) List existing network services
$ networksetup -listallnetworkservices
An asterisk (*) denotes that a network service is disabled.
Wi-Fi
Bluetooth PAN
Thunderbolt Bridge

$ # Prepend DNS servers with localhost
$ networksetup -setdnsservers Wi-Fi 127.0.0.1 x.x.x.x y.y.y.y z.z.z.z