Glossary
Destination Port
The destination port is a 16-bit field in TCP and UDP headers that identifies the port number of the receiving application. It tells the transport layer which application on the destination host should receive the packet's data.
Technical Details
Size
16 bits (2 bytes)
Range
0 – 65535
Well-known ports
0 – 1023 (requires privileged access)
Registered ports
1024 – 49151
Dynamic/Ephemeral ports
49152 – 65535
Protocols
TCP, UDP
Related Concepts
Service Identification
Destination ports allow a single host to run multiple services simultaneously. Port 80 serves HTTP, port 443 serves HTTPS, port 22 serves SSH, etc.
Port Forwarding
Routers and firewalls can forward traffic from a public port to a different internal port and host based on the destination port number.
Load Balancing
Load balancers use destination ports to distribute incoming traffic across multiple backend servers running the same service.
Used In Protocols
TCPUDP