InetSocketAddress(URL, PORT) takes lot of time to throw exception

Question

1. Connection to Internet is removed. DNS is properly configured.

   Try running the following line:-

   new InetSocketAddress(URL, PORT);

   This takes around 56 seconds to throw UnknownHostException.

2. Connection to Internet is removed. DNS is not configured.

   Try running the following line:-

   new InetSocketAddress(URL, PORT);

   This takes less than 2 seconds to throw UnknownHostException.

Why?

Is there any solution to quickly throw Exception in Scenario 1?