CompTIA Network+ N10-004: 1.2 – Commonly Used TCP and UDP Ports

| Mar 29, 2009 | Comments 5


If you’ve spent any amount of time around networks, you’ll know that the most popular applications use well known TCP or UDP ports to communicate. In this video, we’ll tell you the ports you’ll need to memorize to get through your CompTIA Network+ certification exam.

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Filed Under: CompTIA Network+ N10-004

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  • Tom Massoni

    Professor Messer,

    Just in case it comes up on the Net+ test I just wanted to clarify what port DHCP uses. In your Net+ module Commonly used TCP and UDP ports you state DHCP is on port 67 but on your exam cram sheets for A+ you state it is on port 68.

    Thank you putting together all these videos. You have done a truly great thing for all of us and I really do appreciate all you have done.

    • http://www.ProfessorMesser.com Professor Messer

      Tom, I’ve clarified the wiki page to properly include the explanation of the server using DHCP over udp/67 and the client using udp/68. Thanks for the comment!

  • whisptech

    How come in all the books and even in your video when it comes to snmp they discuss udp port 161 but never tcp port 161? I find it curious because they discuss dns on both udp and tcp port 53.

    • http://www.ProfessorMesser.com Professor Messer

      whisptech -

      Most applications only use one transport protocol to communicate across the network, so you’ll only see an application use tcp or udp, but rarely both. Domain Name System is one of those rare protocols that will use ucp packets to accomplish one type of task and tcp packets to perform other tasks. In practical use with most applications, you’ll only see them using one transport protocol.

  • Aucado54

    Once again you have rocked me. This video seems to go a bit fast but as you said there is much to memorize so not much point keeping repeating one self. HMM thinking “flash cards” for this one.
    Thank you for the great things you are doing to spread the knowledge.