ephemeral port การใช้

• Microsoft Windows operating systems through XP use the range 1025 & ndash; 5000 as ephemeral ports by default.
• On servers, ephemeral ports may also be used as the port assignment on the server end of a communication.
• Previous versions, including the Berkeley Software Distribution ( BSD ), use ports 1024 to 5000 as ephemeral ports.
• Ports 49, 152 through 65, 535 are ephemeral ports and are used as temporary ports primarily by servers.
• They also are used as ephemeral ports, from which software running on the host may randomly choose a port in order to define itself.
• Conversely, the client end of a connection typically uses a high port number allocated for short term use, therefore called an ephemeral port.
• Clients connecting to a service usually use ephemeral ports, i . e ., port numbers assigned only for the duration of the transaction at random or from a specific range configured in the application.
• NAT " port preservation " for outgoing TCP connections is crucial for TCP NAT traversal, because as TCP requires that one port can only be used for one communication at a time, programs bind distinct TCP sockets to ephemeral ports for each TCP communication, rendering NAT port prediction impossible for TCP.