Port Numbers Explained | Cisco CCNA 200-301
HTML-код
- Опубликовано: 3 окт 2024
- Join the Discord Server!
/ discord
---------------------
MY FULL CCNA COURSE
📹 CCNA - certbros.teach...
FREE CCNA FLASHCARDS
🃏 CCNA Flashcards - certbros.com/c...
HOW TO PASS THE CCNA
📚 Get a great book - amzn.to/3f16QA5
📹 Take a video course - certbros.teach...
✔ Use practice exams - www.certbros.c...
SOCIAL
🐦 Twitter - / certbros
📸 Instagram - / certbros
👔 LinkedIn - / certbros
💬 Discord - www.certbros.c...
Disclaimer: These are affiliate links. If you purchase using these links, I'll receive a small commission at no extra charge to you.
---------------------------------------------------------------------------------------------------------------
In the last video, we looked at the layer 4 protocols TCP and UDP. Layer 4 is also responsible for choosing port numbers.
So why do we need port numbers? The example I give here is the postal service. To get post, you install a letterbox (at least here in the UK). This letterbox allows the postal service to access your home.
Network applications work in the same way. If you want to communicate over a network, you must allow some means of access to your device.
Let's say we want to access a web server. We type in the web address (also known as a URL) of the site we want to visit.
The first thing the computer does it convert that URL to an IP address.
This is done by using DNS, but we will cover than in another video. For now, just know it coverts web addresses to IP addresses.
The computer then sends the request to the webserver. The server will then look at the destination port to find out which application to send this data to. It can do this because there is a standard that port numbers follow.
When we made our web request, our computer knew we were trying to access a HTTP site. So it added the destination port number 80 to the TCP header.
The computer will also choose a randomly generated source port to receive reply’s on.
Several port numbers are called well-known ports. These are common protocols that have been assigned port numbers.
Examples of well-known port numbers are HTTP(80), HTTPS(443), SMTP (25).
0 - 1023: Well-known port numbers.
1024 - 49151: Registered ports that companies have registered IANA
49152-65535: Dynamic ports
Resources:
tools.ietf.org...
www.iana.org/a...
#ccna #cisco #networking
![KAYTRANADA - Witchy (feat. Childish Gambino) [Official Video]](http://i.ytimg.com/vi/jGK3YVmGZ3Y/mqdefault.jpg)
Wow, I don’t know why others can’t explain this basic idea clearly. Thank you.
Thanks! Great to hear you liked the video. Thanks for watching!
thanks i got point
F::5
@Certbros Sir how can I find port on my window 10 laptop
Letting you know that I passed my CCNA 200-301 this week and your videos helped me do it! Thank you!
Congratulations!! These are the comments I love the most!! Nice work 👍
I just begun my course with cisco so i will be a tier 2 engineer
Yes! Port numbers, came at a a great time. If you guys would make a video on Cryptography or Encryption, it would be too great!
Thanks Ron. Glad the video helped. Good suggestion. I plan on making some security videos in the future. 👍
Never heard this simple yet comprehensive explanation in any of my computer classes in university.
Thanks for this great video
Thank you so much for the great explanation!
The best sentence in this video was "IP address gets the data to the computer, but it's the port number that gets the right application"
Wrote it down for myself.
Thank you! My teacher has made port numbers sound like something that one can only understand with multiple doctorates
Thanks Christina! Great to hear the video helped you out. Port numbers are pretty simple once you get your head around it.
LOL. true story!
🤣🤣
🤣🤣🤣🤣🤣 comment is so underrated
sir you are the perfect teacher ever i have seen you giving an every real time example for each topic this makes me practically strong.loved your teaching
i am from france and I still understand your explanation better than my own teacher thanks a lot m8
😊😊😊😊😊😊
Thank you, your video took the confusion out of understanding what Ports are and how they work.
Thanks Denise! Great to hear it helped.
You nailed it. A neat presentation.
Thank you for the simplification in the explanation.
No problem at all. Glad you liked it Ogiri 😀
Wow finally now i understood why a port is required
Continue posting videos that this. You are a great teacher
That practice using powercell is so helpfull, i am newbie and i need more practical like this, especially when explaining about tcp/ip model, would like to know what exactly is happening inside the computer during encapsulating and decapsulating data from application layer up to physical layer. Or maybe explain in some 3rd party software like wireshark.
"wrong": your house address is your IP, your name on the letter is your port because you can have many people living under this address.
Or, if instead of house if it is a block of flats: house number is an IP, room number is the port. But then we need also a "sub port number" for the names of people living in this room ;-)
Crystal Clear Explanation 👍 Thank You.
Glad you liked it
Thanks!
Everyone else only explained how ports are used without getting into what they actually are or how they operate which made it a lot harder to really wrap my head around them.
You provided a really great balance of explaining that without getting overly complicated.
great explanation, my professor doesn't actually teach anything and tells us to just read the material on netacad. Ive been lost since the second week. your videos have helped me get some clarity from what i have been reading.
Glad these videos are helping 👍 Sorry to hear your professor isn't much help.
Hie thanks for a great review, im attempting to transition fro the construction industry into IT and i go introduced to the cisco skills for all program. I wasnt sure about its value but listening to this review has encouraged me a lot. My goal is cybersecurity and im not sure if i should leave the networking and focus on the security or i should run with both.
OMG! That was extremely informative. The person explanation was on point. Even the most stupid Person in the world could understand that intel. Thank you kindly Mr 🙏🏻
0:27 layer 4 - transport
0:32 also responsible for choosing *port number*
0:41 why port number is needed
THANK YOU SO MUCH!!!! I was struggling with Ports but you just explained it so easily. Thanks again 🙏 💕
You're welcome! Great to hear it helped 👍Let me know if you have any questions.
@@Certbros thanks now I can boot people yay🤟🤟
Thank you! Helped me so muc with my homework
Excellent explanation!
Thank you!
That's great to hear! Glad you got some value from this.
Great video. but at 7:10 I think you meant the CLIENT is not sending the request to the web application port, not the SERVER.
Thank you very much good explanation 💯
Thanks! Great explanation!
Thanks! Appreciate the comment 👍
could you please do an updated tutorial about STP ?
btw great way of explaining new concepts to beginners !!
Thanks Amen! I appreciate the support.
STP will be updated in the full course. It will have the same information it will just look and sound better.
@@Certbros Looking forward to it
Awesome video amigo , thank you 🙏🏼🙏🏼🙏🏼🙏🏼
Perfectly explained, thanks. Thumbs up from me 👍 and my sub! Cheers - Neil (UK)
Amazing.. thanks
Thank you Aji! 👍
After running netstat -n and viewing the listed connections, is there a way to find out what each connection is? I would like to know what each of the connections are that are showing on my computer :)
Also huge thanks for the incredible and easy to understand content!💙 10/10🙌🏼
If you run netstat -no it will show you the process ID (PID). You can then check the PID in task manager or use the command tasklist.
Great to hear you liked the video!
@@Certbros Thank you, it helps!
amazing videos!!
Thanks! very useful
Thanks Rani!
Well explained
Give a video about SSL completely
Thanks for sharing
Thank you! helped a lot
Thanks Omar! Great to hear 👍
You truly deserve more likes and views. Arigato!!!
Thanks Tanzeel! Great to hear you liked the video 👍
Wow, thank you so much
No problem
are you the same person who does videos for the crossfader channel dj tutorials? lol your voice sounds extremely familiar
Just saw your excellent video explaining TCP UDP and was going to ask if there was one on ports when this auto played haha. Awesome and exactly what I was wanting to know next
Great to hear! IP Addresses next 👍
This is a really informative and fruitful video. I nearly took notes for every sentence in the video.
Thank you Conor! Glad I could help!
Beautiful explanation, thank you so much for your hard work!
You're welcome! Thanks for the comment 👍
I have come to realise if you can't understand subnet masks and subnetting you can't understand networking outside of your home .... I have been learning about ip addresses for over 1 week now.. 😭😭😭😭😭😭🙁😔.... Wish I was in the room just to ask couple small questions that need comfirming
Keep going Ron, you'll get there.
Ask any question you have!
Port 80 is my favorite 😂
Awesome!
Thanks!
May be I ll be the first one to dislike!! Why I didn't find you earlier ????.. Precise and upto the mark!! Great work!!
Great tutorial......just one question, what if multiple host are requesting connection for port 80 ?? how multiple host will connect to that server?
Thank you Shubham. Thousands of hosts could connect to the same server on port 80 at the same time. It's the source port and IP address that allows the traffic to be uniquely identified.
@@Certbros Thank you, appreciate your quick response !
Crystal clear on the basics ! good explanation with the figures
Thank you!
This is an excellent video!!! OMG it helped me A LOT!!! to understand Ports numbers!!
That's really great to hear! Glad you it helped you out 👍
Best video for this concept in the whole RUclips.....love you guys❤️
Super like!
A-MA-ZING, AM-FUCKING-MAZING AMAZING!!!
Brilliant ... absolutely the best!!
Is it ok to think of your IP address as an apartment building and port numbers as apartment numbers inside that apartment building?
Yes absolutely. Every apartments is a service or application within the computer (apartment building). The numbers are the port numbers. Good analogy!
I have a question.
Why the source port / port of our computers is changing ?
Thanks sir for helping
Please tell about termux port
Thanks😭😭
The ports arnt physical ports, are they? They are just software, right?
Exactly! 👌 There are physical ports as well though. I know...its confusing. It will become clear in no time.
You are amazing...
No! You're amazing!
Quick question. If a computer can connect to a server, but the server cannot communicate with the computer...why do you think that is? Is it that the port number on the computer's firewall isn't open to allow connection?
How are you trying to connect? If it works one way but not the other, I would first check the firewall on the computer like you suggested.
Hello, thanks for the explanation
Ok, after I check my connections what should I do if my desired connection is missing from the output list of `netstat -n`?
I want to establish connection between certain local address my_IP:3334 and foreign_IP:some_port. How can I reach it?
I want to make handshake between PC and and raspberry.
Simple but intuitive and powerful explanation! thank you!
That's really great to hear! Thanks for the comment. Glad you liked it.
how does this channel have only 50k subscribers
Thank you! You explained so clearly.
I spent $7000 HKD to join a CCNA(full track) in Hong Kong local centre, and it can't explain such thing easier. Better I spend it here.
could you please do an updated tutorial about STP ?
btw great way of explaining new concepts to beginners !!
Shielded twisted pair?
@@Rickety3263 Spanning tree protocol
How did you get to know about your source port number? could you please explain
Please correct me if I’m wrong. But my understanding of this is that port numbers are assigned to services or protocols so when we the client reach out to a server, that server knows, because of the port number, which protocol to use while we’re communicating?
Super... I just tried netstat command got information in details .. Thanks you so much..
Great to hear! Glad you liked the video!
Dumb question of the day. Are you saying that a person would need to memorize all the "well known" port numbers for the exam?
Thanks!
Thanks for making such videos man, 👍
It's helpful alot
I understood the idea of giving a random port to the source because the port is used in the reply.
Thanks.
Also, I learned some new ports yet I would love to hear from you kore deeply about the 12 famus ports you showed because you did not go over all of them and you did not put enough information in each so I would like to hear more from it.
However, wonderful video I learned from you in this video some important concepts and it sharped my knowledge.
Thanks for the feedback and I'm glad you liked the video.
balance of explaining that without getting overly complicated😅
are those port number physical port number on the server or logical just like IP?
Does the poet number 9988 is free to choose or a port number, which is strictly defined for a specific protocol?
How many ports does a Cisco port have?
Fuck university, all my homies learn from RUclips
Thank u sir
a very helpful and informative video! Thankyou for educating me.
You're welcome. Glad it was helpful!
Best explanation I've heard on this topic...Thumbs up!
Thank you! Really glad to hear this 🙏
Sir please add more videos please you videos are very very very very very and very amazing
Thanks bro, your way of explaining these complex topics is the best. I learnt a lot from you. Thanks a lot. You earned a new subscriber
Thank you Mithun! Happy to help 👍 Welcome to the channel.
Ty sir
You're welcome!
OMG!!
Some tutorials are just too short but they explained everything you're looking for
Thank you very much
Thank you Ibrahim! Really great to hear you liked the video.
Good luck with everything.
Great....
Thanks 👍
I absolutely like your explanation guys! Keep on doing an amazing job!
But what exactly are ports? Is it some kind of software?
Thanks for this video :-) 👍
cool
very crisp and spot-on, love your videos. Could you please make a video on Virtualization.
Thanks! Great to hear you liked it. Yes, virtualization is on my to-do list 👍
very good video,which programm you use at timeline 4:32?
What can I use instead of powershell if I have a MAC?
Thanks for the video 🤠
No problem 👍 Glad you liked it!
Nice video.Thanks
Thank you!
Thank you very much am from Ethiopia
how web server know the src port number of computer when it responds to the computer's request?
Good question! The source port number is included in the original request. The web server then reverses them. Hope this helped!
Bhai tuze 21 topho ki salami🙏👍