What does port number ZZZZ mean?
Port numbers are divided into three ranges: • The Well Known Ports are those from 0 through 1023. These are tighlty bound to services, and usually traffic on this port clearly indicates the protocol for that service. For example, port 80 virtually always indicates HTTP traffic. • The Registered Ports are those from 1024 through 49151. These are loosely bound to services, which means that while there are numerous services “bound” to these ports, these ports are likewise used for many other purposes. For example, most systems start handing out dynamic ports starting around 1024. • The Dynamic and/or Private Ports are those from 49152 through 65535. In theory, no service should be assigned to these ports. In reality, machines start assigning “dynamic” ports starting at 1024. We also see strangeness, such as Sun starting their RPC parts at 32768.
