How do you all remember common port numbers?

NvermindNvermind Member Posts: 35 ■■□□□□□□□□
Do you just walk around muttering them to yourself for a day or so?

Maybe there are some little rhymes or somethings cos memorizing them is driving me nuts!

Thanks in advance,

Leave the monkies alone! They've got problems enough as it is!


  • Options
    jovan88jovan88 Member Posts: 393
    You just pick it up eventually, like phone numbers and passwords it just sticks to you the more you use them.
  • Options
    ColbyGColbyG Member Posts: 1,264
  • Options
    NvermindNvermind Member Posts: 35 ■■□□□□□□□□
    bah! had a feeling you would all say that!

    Thanks for your answers

    Leave the monkies alone! They've got problems enough as it is!
  • Options
    poguepogue Member Posts: 213
    I actually visually remember the two pages in my ICND1 study guide with the port numbers.

    Also, to memorize, start by reciting the first 2 or 3 port numbers in your head, along with what function they provide (FTP, FTP Control..)

    Then, add the next on the list, and keep repeating the whole list you've memorized. Keep repeating this step, and you'll be able to recite the whole list in your head.

    The port number and function should come easily if you bear down and concentrate while memorizing. If you have a hard time memorizing whether they are UDP/TCP, just remember, the first part of the list is TCP. That way, all you have to do is remember that it is at DNS that you transition to both UDP/TCP.

    Use little "tricks" to remember whether the functions in the middle of the list are UDP or TCP.

    "Trivial" File Transport Protocol is "trivial", so it does not need reliability, so it is UDP. Also, it is the "sexy" protocol used to load stuff on a router. "Sexy" = port "69".

    Depending on how you personally memorize best, you have to develop little "tricks" like this to help yourself.

    Here's another example. Let's take the first three well known port numbers that Cisco wants us to memorize:

    20 FTP
    21 FTP Control
    22 SSH

    They are all TCP. To remember them as a unit together, think of some memorable words.


    The way I memorize, these words are easy to memorize. I now know the first two ports begin with F, and since they end with a T, I know they are TCP. I know the third port number has an SH in the name, and with these words, all I have to do is remember the numbers 20-22 and associate them with this three words block.

    Now, instead of associating each port number individually with it's function and whether it is TCP or UDP, I can just remember

    FiT FiT faSHisT, 20-22

    And this is enough for me to know the first three port numbers. Build similar type words blocks for the other port numbers, and it becomes a lot easier to remember.

    This is the same concept as remembering the phrase:

    All People Some Times Need Data Processing

    in order to remember the order of the levels of the OSI model.

    Change hard to remember concepts into easy to remember words.

    Hope this helps.

    Currently working on: CCNA:Security
    Up next: CCNA:Voice
  • Options
    networker050184networker050184 Mod Posts: 11,962 Mod
    Like others stated they start to stick after a while. For the ones that don't I keep this bookmarked icon_wink.gif
    An expert is a man who has made all the mistakes which can be made.
  • Options
    PashPash Member Posts: 1,600 ■■■■■□□□□□
    I am kinda fortunate in that I often make changes to big 6509 switches with a monster amount of acl's on them, when you know the "human word" or port number for a lot of rules then it kind of sticks for everything else.

    As others have said, with time it will stick like glue.
    DevOps Engineer and Security Champion. https://blog.pash.by - I am trying to find my writing style, so please bear with me.
  • Options
    Cal_0808Cal_0808 Member Posts: 12 ■□□□□□□□□□
    Try recording yourself reading them all and then putting them on an mp3 player or your phone or something and listening to them once in a while, that worked for me.

    A friend of mine gave the hint to put them all on seperate post it notes and post them somewhere you look at everyday, bathroom mirror somewhere like that
  • Options
    blackninjablackninja Member Posts: 385
    Not too hard to remember them after while, it sort of just happens. Stressing about it is prob the worse thing you can do.

    If you have a lab or PT, setup some ACLs with the diffferent port numbers. Or when see or read about a certain protocol say the port number. e.g. When you receive an email say - tcp port 110. When you send an email say - TCP port 25, T.F.T.P. - UDP and we we all love this one ;)

    Before you'll realise you'll know all the common ones.
    Currently studying:
    CCIE R&S - using INE workbooks & videos

    Currently reading:
    Everything. Twice ;)
  • Options
    tierstentiersten Member Posts: 4,505
    You just know them after a while... At least for the more well known ports anyway. I wanted to know the port number for something obscure then I'd look it up
  • Options
    rakemrakem Member Posts: 800
    Google remembers them for me!
    CCIE# 38186
  • Options
    Forsaken_GAForsaken_GA Member Posts: 4,024
    You get used to the port numbers after awhile just from working with them. For everything else that's common, I can **** and use /etc/services on debian installs to check wtf the protocol is. For anything that's esoteric, google is my bestest buddy
  • Options
    dwcoffindwcoffin Member Posts: 6 ■□□□□□□□□□
    I came up with a mnemonic for memorizing common TCP protocol ports.

    "For Some Techs Simple Deeds Have Put Nice Networks In Harm"

    Protocol Port Phrase
    FTP 21 For
    SSH 22 Some
    Telnet 23 Techs
    SMTP 25 Simple
    DNS 53 Deeds
    HTTP 80 Have
    POP3 110 Put
    NNTP 119 Nice
    NTP 123 Networks
    IMAP4 143 In
    HTTPS 443 Harm

    I remember the first ports start with 21, 22, 23.
    Last two digits of previous 2 ports equals 5 so next is 25;
    the reverse of 25 is 52 so next port is 53;
    I always knew HTTP is 80 and POP3 is 110.
    NNTP with 2 N's makes me think of NiNe so its 119.
    I know NTP is 123
    IMAP4 has a 4 which leads me to 143,
    Put in another 4 for HTTPS so its 443.

    Maybe I have Aspergers or something but I was pleased to come up with the mnemonic phrasing and seeing the numbers in the numeric order helped me come up with mental triggers laid out above for remembering the port #s. Ask what they are individually and I am hard pressed to tell you without doing my exercise.

    Just my 2¢ and if it helps great.

    Good Luck
  • Options
    Cisco InfernoCisco Inferno Member Posts: 1,034 ■■■■■■□□□□
    i always make a chart on paper and pin it above my desk on the wall.
    2019 Goals
    CompTIA Linux+
    [ ] Bachelor's Degree
  • Options
    NetworkVeteranNetworkVeteran Member Posts: 2,338 ■■■■■■■■□□
    Nvermind wrote: »
    Do you just walk around muttering them to yourself for a day or so?
    The ones I know I've simply used so many times. The ones I don't I just Google if I need them.
  • Options
    pamccabepamccabe Member Posts: 315 ■■■□□□□□□□
    Some good ideas here, glad I looked at this thread. There are a couple I get mixed up on so I am still memorizing these before my exam. One thing that has really helped me is flash cards. There is a program called Anki that lets you create your own flash cards. You can export the cards you create to a smartphone also for those on the go. I love the program and it really helps me memorize concepts. I use them whenever I have time.
  • Options
    dazl1212dazl1212 Member Posts: 377
    For the N+ at least i just continously did the quiz on here for about a week
    Goals for 2013 Network+ [x] ICND1 [x] ICND2 [ ]
  • Options
    kurosaki00kurosaki00 Member Posts: 973
    I dont... lol
    I only know like 6 because I work often with them or used to work often.
    I also know some other random ones because of work, like IPsec-ESP port 50
    because I did some configuration in my old job in the firewall

    You will learn some for your cert exams, but the rest you will pick up as you work with em
  • Options
    nickelitonickelito Member Posts: 54 ■■□□□□□□□□
    I did this when learning for the ccent.. now ive forgot them, but like someone said. the more you use them the harder they'll stick:

    22H (SSH) = 22
    T3LN3T = 23
    5MTP (SMTP) = 25

    ..just to name a few.
  • Options
    d6bmgd6bmg Member Posts: 242 ■■■□□□□□□□
    Just by memorizing it. And after working some time with them, you just can't forget them.
    [ ]CCDA; [ ] CCNA Security
  • Options
    SteveO86SteveO86 Member Posts: 1,423
    As time goes on and you work with more an more protocols they will just stick.

    I started out remembering the ones from the CCNA/Network+ material, as I got deeper in the world of networking and worked with ACLs and FWs that knowledge quickly.

    You will also slowly pick on port numbers when you start troubleshooting using tools like NetFlow and TCPDump/WireShark
    My Networking blog
    Latest blog post: Let's review EIGRP Named Mode
    Currently Studying: CCNP: Wireless - IUWMS
  • Options
    JasionoJasiono Member Posts: 896 ■■■■□□□□□□
    IMAP - ILoveYou - 143 lol
  • Options
    GoodBishopGoodBishop Member Posts: 359 ■■■■□□□□□□
    To use a line from Fairly Oddparents... "Internet!"
  • Options
    powmiapowmia Users Awaiting Email Confirmation Posts: 322
    I use linux, it has a file /etc/services that contains all of the port numbers... so if I want to find out which port is imap:

    me@null:~$ cat /etc/services | grep imap
    imap2 143/tcp imap # Interim Mail Access P 2 and 4
    imap2 143/udp imap
    imap3 220/tcp # Interactive Mail Access
    imap3 220/udp # Protocol v3
    imaps 993/tcp # IMAP over SSL
    imaps 993/udp

    Cisco also keeps a list for NBAR that is viewable on routers:

    null#sh ip port-map | include imap
    Default mapping: imap tcp port 143 system defined
    Default mapping: imap3 tcp port 220 system defined
    Default mapping: imaps tcp port 993 system defined

    You get used to the numbers eventually, in the mean time... aside from pop quizes, you don't need to memorize. You just need to know how to get the answer quickly.
  • Options
    Master Of PuppetsMaster Of Puppets Member Posts: 1,210
    Yes, I am a criminal. My crime is that of curiosity. My crime is that of judging people by what they say and think, not what they look like. My crime is that of outsmarting you, something that you will never forgive me for.
  • Options
    MinaryMinary Member Posts: 74 ■■□□□□□□□□
    I really like Mnemonics. I know most of the ports but there are some I don't use enough yet to

    I have borrowed from above and added a word: For "Food" Some Techs Simple Deeds have put Nice Networks In Harm




































    It starts at 20 , 21, 22, 23
    25 = 2+3 from 23
    53 is the reverse of 52 "+ 1"
    80 = 5 + 3
    110 = I justt know it
    119 = has 2 N "Nines"
    123 = Rythms with NTP
    143 = has a 4 in it
    443 = put in anther 4

    I created a way to remember the Cisco Notifications using a story which I will put in a seperate post.
  • Options
    ande0255ande0255 Banned Posts: 1,178
    I made a ton of flash cards for random commands, port numbers, IPV6 addresses, etc. That's the only way I can memorize something is by answering it in question format over and over again.
  • Options
    RAMBUSRAMBUS Registered Users Posts: 1 ■□□□□□□□□□
    Wanted to say thanks to you for posting your thread on ports, your mnemonic worked great. I studied last night on ports and used your suggestion. i sat down and wrote this down on the pad provided at the center before i started the test. boom,worked like a charm.
  • Options
    MJohnsonresMJohnsonres Member Posts: 31 ■■□□□□□□□□
    I like to use Quizlet and Encore (Web and App versions).

    Someone probably already created a set of flash cards for Network Ports.

    1st Create some flash cards ( Port Number on one side, Description on the other)

    2nd Create another set of flash cards (Port Number and Short Description on one side, and Detailed Description on the other side).

    * or good ole paper flash cards, print the list and tape them to the cards and have at it.

    Devote 30 minutes in the morning, afternoon and evening.

    Also if you make groups it will make it easier to remember groups of ports.
    i.e. Trival Gophers, Finger, Apples (69, 70, 79, 201)

    You can also try: https://memorize.com/network-port-number/benzart

    Hope this helps
  • Options
    beadsbeads Member Posts: 1,531 ■■■■■■■■■□
    You will once you start using them a few times. Working inside a firewall configs and initial setup work wonders!

    - b/eads
  • Options
    Mike7Mike7 Member Posts: 1,107 ■■■■□□□□□□
    Spend time configuring a firewall, analyzing IPS logs and troubleshooting app network connecting issues.
    Run netstat -anb to view listening services on your PC/server, and to configure host firewall to allow a certain service.
    You will soon remember ports used by common apps and services, P2P software, remote admin software and even malware.

    There was one exam I took where you are required to configure firewall to allow a certain service through. The knowledge helps.
Sign In or Register to comment.