I have two machines. Both have access to the internet.
A) Base deployment machine. It has installed on it,
the Portal, Server, Data Store, Server Web Adaptor and the Portal Web Adaptor
It also has a public IP.
GeoEvent Machine. It has,
GeoEvent Server
It only has a internal IP address.
The GeoEvent Server needs to have its own 'GeoEvent Web Adaptor' inroder to federate the GeoEvent Machine with the base deployment machine. See below federation dialog requiring a web adaptor URL.

Where should the 'GeoEvent Web Adaptor' be installed? On A or B?
Will the 'GeoEvent Web Adaptor' be used for any communication?
As I understand GeoEvent Server, one can be directly send inputs to geoevent using '<geoevent domain/ip>:<port>' for certain input connectors and the only use of a geoevent web adaptor is for federation with a base deployment.