Basically, you only need database connectivity between the two machines. What ever port you set your listeners to use, you will need those ports reachable on their respective server.
“Log shipping” is not really a part of data guard. Changes are shipped through a database connection and logs are written out onto each server.
This does not include when you are setting up your physical standby’s. If you are using NFS or CIFS to share your files for creating the standby, you will need the native ports accessible.