Chapter 20. Understanding Protocols

Protocols provide the common language for devices to talk, and they also provide the rules for communicating. To put this into context, Chapter 18 covers devices such as routers, switches, and computers. Chapter 19 covers the different types of cables and how they connect the devices together. This chapter covers many of the common networking protocols.

Exam 220-801 objectives in this chapter:

  • 2.3 Explain properties and characteristics of TCP/IP.

    • Client-side DNS

  • 2.4 Explain common TCP and UDP ports, protocols, and their purpose.

    • Ports

      • 21 – FTP

      • 23 – TELNET

      • 25 – SMTP

      • 53 – DNS

      • 80 – HTTP

      • 110 – POP3

      • 143 – IMAP

      • 443 – HTTPS

      • 3389 – RDP

    • Protocols

      • DNS

      • LDAP

      • SNMP

      • SMB

      • SSH

      • SFTP

    • TCP vs. UDP

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