Network protocols are rules for device communication, with key examples including TCP/IP (foundational internet protocols), HTTP/S (web browsing), FTP (file transfer), SSH (secure remote access), DNS (name resolution), DHCP (IP address assignment), and SMTP (email), each using specific ports (like 80 for HTTP, 22 for SSH, 53 for DNS) to enable services, ensuring data flows reliably across the internet for applications from web pages to email.
Core Protocols & Ports
- TCP/IP (Transmission Control Protocol/Internet Protocol): The fundamental suite for internet communication, with TCP ensuring reliable, ordered delivery and IP handling addressing/routing.
- HTTP (Hypertext Transfer Protocol): For fetching web pages (Port 80).
- HTTPS (HTTP Secure): Encrypted HTTP for secure web (Port 443).
- FTP (File Transfer Protocol): For transferring files (Ports 20, 21).
- SSH (Secure Shell): Secure remote login/command execution (Port 22).
- DNS (Domain Name System): Translates domain names to IP addresses (Port 53).
- DHCP (Dynamic Host Configuration Protocol): Automatically assigns IP addresses (often UDP, Port 67/68).
- SMTP (Simple Mail Transfer Protocol): Sends emails (Port 25).
Other Important Protocols
- UDP (User Datagram Protocol): Fast, connectionless protocol, good for streaming/gaming, allows some data loss.
- HTTPS (HTTP Secure): Secure web browsing (Port 443).
- POP3/IMAP: Email retrieval protocols.
- RDP (Remote Desktop Protocol): Remote access to Windows desktops (Port 3389).
- ICMP (Internet Control Message Protocol): Network diagnostics (like
ping). - ARP (Address Resolution Protocol): Maps IP to physical (MAC) addresses.
- Telnet: Insecure remote login (Port 23).