This Feature restricts the Zones to be watched only in a particular website or domain so that there will be no unauthorized viewing and complete protection for your copyrighted content. You can also specify a particular IP on which the content can be played.
In order to access Domain Lock feature :
Kindly note that we are not recommending to use Domain Locking for HLS. It's mainly designed for RTMP. Domain Locking will work only with clients that use referer, Mainly with Flash player. It will work only with simple embedding schemes. Also if you want to use unique domain names in this field like teststream.com, http://www.teststream.com, www.teststream.com, www.123-teststream.com etc the best option to enable domain lock for teststream.com is to add like this : *.teststream.com.