When configuring a Citrix NetScaler to load balance Exchange 2013 or 2016 you may want to create a load balancing virtual server without an IP and port combo. The reason is that you're going to bind the load balancing virtual server will to a content switching virtual server, clients won't access the lb vserver directly.
Many blog posts as well as Citrix documents as for instance their most recent Exchange whitepaper Microsoft Exchange 2013 with NetScaler: Authentication and Optimization tell you to select Not Directly Addressable. Unfortunately the Directly Addressable check box is no longer available in NetScaler 10.5 and newer.
Well, the feature is still available but has been renamed and moved to another location. If you're using the web interface, choose Non Addressable from the IP Address Type drop-down list no create a virtual server which is not directly accessible.
Maybe it's just me, but I could not found the cmdline alternative in the lb vserver section of the NetScaler Command Reference. So I create one with the web interface and looked it up in the config. Apparently all we need to do is enter the IP address and port number as 0.0.0.0 0.
add lb vserver my_lb_vserver ssl 0.0.0.0 0
In summary, the checkbox for Directly Addressable is replaced with the Non Addressable option in the IP Address Type drop-down list. If you're using the cmdline, set the IP address and port number as 0.0.0.0 0.