Service Ports: The Door to the Programs on Your System
Network-based services are programs running on a machine that other computers on the network can access. The service ports identify the programs and individual sessions or connections taking place. Service ports are the numeric names for the different network-based services. They are also used as numeric identifiers for the endpoints of a particular connection between two programs. Service port numbers range from 0 to 65535.
Server programs (that is, daemons) listen for incoming connections on a service port assigned to them. By historical convention, major network services are assigned well-known, or famous, port numbers in the lower range from 1 to 1023. These port number–to–service mappings ...
Get Linux Firewalls, Third Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
