Port
A port is a numbered communication endpoint used by network protocols to identify which service should receive traffic.
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HTTP
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Well-Known Ports
Standardized TCP/UDP ports (0-1023) reserved for common services, like 22 for SSH, 80 for HTTP, 443 for HTTPS. Foundational networking knowledge defenders use constantly.
3
lessons
Ephemeral Port
A temporary transport-layer source port selected for a connection from the operating system's configured dynamic range.
1
lesson
HTTPStart here
HTTP is the protocol browsers and applications use to request and transfer web content.
9
lessons
SMTP
Simple Mail Transfer Protocol: the protocol that moves email between servers across the internet. Foundational to email infrastructure and a target for both abuse and detection.
1
lesson
SSH
Secure Shell: a cryptographic protocol for remote shell access and other secure connections, widely used for Linux/Unix administration and as a heavily targeted attack surface when exposed.
1
lesson
Related Lessons
12 lessons cover this concept · showing the first 8Web Architecture and Request Flow
General Beginner
URLs, Domains, DNS, and Hosting
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HTTPS and TLS in the Browser
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Cookies and Sessions
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Authentication and Authorization in Web Apps
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Input Handling and Injection Attacks
General Beginner
CSRF, CORS, and Security Headers
General Beginner
Defensive Web Thinking
General Beginner
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