I'm loading up Nexus on a VM with all outbound ports locked down. I need to know what outbound ports Nexus uses to do whatever it does in all scenarios.
Let's assume the repositories it connects to use their corresponding standard ports.
It seems to just connect to port 80 for the usual external repository.
You could easily configure a repository that uses another port, but you should be able to see one in the list of repos in Nexus' web interface.