Adding secondary replica from different subnet for AlwaysON If I understood the configuration of setting up a multi subnet AG setup where 2 nodes are in one datacenter and the 3rd node in another, I was under the assumption that we require 2 listner ip's - 1 listner ip for each subnet. Is this not the case? I was going through this article today, where the author no where mentions about creating another listner for a multi subnet AG setup. Can someone please clarify if we require a different listner ip for the second subnet or not? 

Refering to https://www.mssqltips.com/sqlservertip/4598/add-secondary-replica-to-existing-sql-server-alwayson-availability-group/#comments

Thanks!
IP address for each subnet. Documented here: https://msdn.microsoft.com/en-us/library/hh213080.aspx#Prerequisites