If you want to know which ports on system are reserved by services, run this command
WRKSRVTBLE
The service table contains a list of well-known network services and the port and protocol each service uses.
Service Port Protocol
as-admin5-https 2012 tcp
as-admin5-https 2012 udp
as-central 8470 tcp
as-central-s 9470 tcp
as-database 8471 tcp
as-database-s 9471 tcp
as-debug 4026 tcp
as-dtaq 8472 tcp
as-dtaq-s 9472 tcp
as-edrsql 4402 tcp
as-file 8473 tcp