Assigning Port to Listener in AlwaysOn
Right now we are connecting using the Listener\InstanceName


The listener does not actually interact with the Browser service, and thus I wouldn't use this way with a listener - ever.


  I wanted to configure in such a way that just giving the AG_Listener would be enough to connect without using the port explicitly. 


Set the listener for port 1433. The listener uniquely identifies the instance of SQL Server and there can be multiple listeners all using 1433 as each listener has a unique IPv4 and/or IPv6 address. Note that there are other means to which SQL Server can be connected through when there are multiple instances on the same server which may or may be appropriate or correct ways of connecting.