The FMC and managed devices communicate using a two-way, SSL-encrypted communication channel, which by default is on port 8305.Cisco strongly recommends that you keep the default settings for the remote management port, but if themanagement port conflicts with other communications on your network, you can choose a different port. If you change the management port, you must change it for all devices in your deployment that need to communicate with each other.
Reference:
https://www.cisco.com/c/en/us/td/docs/security/firepower/misc/fmc-ftd-mgmt-nw/fmc-ftd-mgmtnw.html

Explanation: The Version 1 format was the initially released version. Do not use the Version 1 format unless you are using a legacy collection system that requires it. Use Version 9 or Version 5 export format. Version 5 export format is suitable only for the main cache; it cannot be expanded to support new features. Version 8 export format is available only for aggregation caches; it cannot be expanded to support new features. Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/netflow/configuration/15-mt/nf-15-mt-book/cfgnflow-data-expt.html