There are a number of reasons why dnsmasq may not work for you after updating Yosemite. First, make sure that your local host (127.0.0.1) is set to the first position of your system settings> Network> Advanced for network devices for which you want dnsmasq to work.

* . DNS- Google, IP- 8.8.x.x .
: https://blog.wwwjfy.net/2014/06/03/some-solutions-to-some-problems-in-yosemite-beta/
"kickstart" dnsmasq, :
sudo launchctl kickstart system/homebrew.mxcl.dnsmasq
, plist , .
/path/to/homebrew.mxcl.dnsmasq.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>homebrew.mxcl.dnsmasq</string>
<key>ProgramArguments</key>
<array>
<string>/usr/local/opt/dnsmasq/sbin/dnsmasq</string>
<string>--keep-in-foreground</string>
</array>
<key>RunAtLoad</key>
<true/>
</dict>
</plist>
, .