"Alexa, ask Subnet Calculator what is the subnet mask for a slash 27?"
"Alexa, ask Subnet Calculator for the subnet mask of slash 21."
"Alexa, tell Subnet Calculator to give me the mask of a slash 16."
Currently, this skill provides the subnet mask for a given network prefix (in slash notation). Future updates will provide network and broadcast address for a given host address, as well as other subnet calculations.