NAT Explained | Overload, Dynamic & Static

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What is NAT?
Network Address Translation (NAT) is used to convert private IP addresses to public IP addresses and vise versa.
The feature was introduced to prolong the life of IPv4 addresses. By using NAT you can convert all your private IP addresses to a single (or few) public address. This means a huge number of public addresses can be saved because the private addresses can be used over and over again in private networks across the world.
Types of NAT
There are three types of NAT, some more common than others but it’s a good idea to know exactly how each one works and how they can be used.
Static
Static NAT is when you manually assign each private IP address + port number a public IP address + port number. This could be used when running web server or mail serve.
Dynamic
The way Dynamic NAT works is by assigning each private IP to a public IP from a manually created pool of available public addresses.
You can use this to merge two networks with the same subnet together. You would configure the connecting routers to make the subnets appear to be different to what they actually are.
PAT (Overload)
Port Address Transaction (PAT) or Overload as it is often called is the most popular version used today.
The way PAT works is it converts the private address + port number to the public address + port number.
#ccna #cisco #networking

[@yohaneranga8827]

I do not normally comment on videos , but as most of the viewers may agree with me , you deserve more subscribers. Your explanations are by far one of the best ,even better than what they call industry experts. Keeping it simple and one explains one thing at a time makes it pretty stress free to watch and understand. Keep it up and I'm looking forward to see more advance networking concepts simplified.

[@Certbros]

Thanks Yohan. Appreciate the comment. Glad it helped you out.

[@schrodinger6991]

I am watching this because my class was cancelled because our school is closed because of the virus, therefor our teacher can't explan the content so he sent as the video.

[@Certbros]

Thanks! It's really great to hear these videos are helping people during this time!

[@mujtabaarfat717]

because its closed becaused u want to study u watched it because u want to learn.

[@FoX84tac022]

Nothing like being supplied free content for a class your paying for... lol

[@schrodinger6991]

@@FoX84tac022 I am not paying for it education in Austria is free

[@FoX84tac022]

@@schrodinger6991 Well fuck me xD

[@avengefulgamer3188]

This is a really great video. Im working on getting my CCNA and this really helped me understand how NAT works after school. thank you for the solid and slow paced information to let it sink in.

[@Certbros]

Good to hear this video helped you out. Thanks for the comment!

[@itaybarok9405]

Thanks. I understood the concept of NAT strongly now and why it is important. Also, I know types of NAT like PAT NAT and static NAT and dynamic NAT. Great and useful video. Keep up with these good staff.

[@andywarrier489]

I am basically a dumb person, but mate, you make me feel intelligent and that is priceless for me. Thanks a ton and cheers!

[@Dragon-Slay3r]

The pinky second finger yesterday was fake thats why they deploy bey cap cover for bullshit 😭 aslong as people make money who cares

[@guidowitt-dorring124]

This is the first video I've seen that properly explains NAT. Most others are too superficial and skip some details that are crucial to understand for the system to logically make sense.

[@infinitelooping]

This video is a marvelous explanation of NAT, one of the bests I have ever seen. Well done

[@lenbrake4982]

Thank you for a carefully explained short clarification!

[@tiramisu2717]

This is a solid explanation of different types of NATs. It has helped me solidify my understanding! Thanks.

[@Certbros]

Thanks Ray!

[@samuelnwadike9042]

i really appreciate your teaching skills, simple and effective direct to the point. i will really love more of your videos you got a new fan. if you have stuffs on CCNA recent stuff or even exam dumps please just send me the link thanks

[@infamousstreaming2899]

I got a computing exam coming up, this video explained it flawlessly compared to the notes. Appreciate it bro! also subscribed :))

[@JP-ws4sv]

mate your videos are really good. your animation and voice really help simplify the essays ive read in CCNA books. thanks !

[@Certbros]

Thanks Jit! Happy it helped

[@Itsweet5533]

0:26 start -- thanks for the video!

[@atharvabet1637]

Truly amazing! Just got what I was looking for. Please keep uploading such wonderful, crisp and informative videos in the upcoming time :))

[@Certbros]

Thank you Atharva. More to come!

[@shajondas9313]

Thank you!!! Your videos are below 10 minutes and in this short time you gave the concrete concept and so much information indeed . Thank you again.....

[@Certbros]

Thanks for the comment! I try and keep these videos as short and simple as possible so it's good to hear its working.

[@ok_gn]

Legend. Great teaching style. Thanks for the video.

[@8686joedog]

Awesome tutorial. What about “open” nat. I remember years ago my xbox would struggle with multiplayer connections because it said my nat was not set to “open”.

[@MrHuzzy93]

Great explanation! Keep the good work up. Highly appreciated!

[@Certbros]

+Hussein Jasin FIRST COMMENT! Thanks!

[@ransfordaddai6992]

Great video., NAT simplified. i recommend this video to anyone struggling to understand this concept. Kindly do more of this video. the graphics, explanation and top notch

[@nileshgujar4310]

You made it so easy to understand, as I read some articles and find myself scratching my head again n again ... Thank you

[@Certbros]

You're welcome Nilesh! Happy to help 👍

[@vinnyseeram6418]

Great video! Would it be correct to say that the key difference between PAT and static NAT is the router building the NAT table vs manual configuration of the NAT table?

[@rikvanbrugge]

By a guy with no IT background at all: already on my sixth video today. Very clear text, good voices, excellent animations. Thanks a lot!

[@Certbros]

Thank you Rik! Really great to hear your enjoying the the content.

[@danteeep]

you explained better than any video on youtube ive checked so far.. thx

[@Certbros]

Thanks!

[@jimyork8196]

You took a somewhat mystifying concept and made it very easy to understand! Thanks!

[@Certbros]

Thanks Jim!

[@arsalalam5998]

great video. looks simple but all the required content in place.

[@umunnahgentle6440]

This is the first time i have been able to understand this NAT lecture. Thanks a lot. Please do you have a video on IS-IS and BGP configurations

[@TeX____]

very good and fast explanation of how NAT works. :)

[@Certbros]

Thanks TeX!

[@DonMalik99]

excellent quick NAT explained, love it. Thanks

[@Certbros]

Thanks Don!

[@kabandajamir9844]

The world's best teacher

[@TabInvader]

Fantastic explanation!!

[@EcripArts]

Glad I stumbled upon this channel. I'm setting up render servers at my office to connect to over VPN from home, with a pfSense server, but I had very limited understanding of why I had to do some things and how these things worked. So it's good to get some more background, I already understand alot more. Great work!

[@Certbros]

Glad to hear the videos have helped you out! It's always great to get these comments. Nice intros by the way!

[@EcripArts]

Thanks, I appreciate it! Most of it is rather outdated actually! And keep up the good work, I like the visual part of the explanation. People have told me about alot of network related stuff but this makes it much more clear to me.

[@ausmanx1161]

@@EcripArts what’s your job tittle now

[@EcripArts]

@@ausmanx1161 Due to illness, unfortunately nothing anymore. I used this for building a render farm for my 3D work.

[@nikhilchoubey5479]

It is really short & simple explanation to understand it easily. Especially the slides representations helps a lot to understand. Thank you!!😊

[@Certbros]

Thanks Nikhil. Happy it helped you out.

[@simray7602]

You deserve more subscriber , good animation make concept simple ,hope for more content coming

[@Certbros]

Really appreciate the support Wind Luo! A lot more content planned in the very near future.

[@speensaba]

keep it up, good explaination.

[@Certbros]

Thanks!

[@dencam]

Thanks for the solid and precise explanation.

[@Certbros]

Very welcome!

[@mehdiroudeau8809]

the best explanation I have ever had

[@Dragon-Slay3r]

In this stupid game the only real fake Jesus is me 😂 If anyone needs an attorney let me know I can find them counters with KZbin in court 😭😂

[@kuvisharamnundlall1736]

This was fantastic, well explained :) Will definitely be reviewing more videos

[@Certbros]

Thanks Kuvisha

[@lnrkothapalli4106]

After 2 or 3 days I got exact information what I am looking for thank u so much

[@Certbros]

Great to hear it! Thanks for watching.

[@Black-xy4pj]

Great video man! Thanks much

[@mashabadigojane9261]

Thanks for the explanantion, extremely useful

[@ramchandrapatil2215]

You explain with very clear and with example. Thanks.

[@Certbros]

Glad you liked it 👍

[@ramchandrapatil2215]

If possible can you please make videos for CCNP. It will really helpful to us and we don't need to anywhere for this.

[@pavelkarvutev8051]

Wow, finally I understand what NAT meant Big thanks, so good!

[@Certbros]

Happy to help! Thanks.

[@BLOEDLINK]

Again, Best explained video's on the net!

[@Certbros]

Thanks Niels

[@jeshbargota7745]

Cheers mate, simple but very effective !

[@Certbros]

Thanks for the support!

[@kychemclass5850]

Great video! Thank you!. When you said data can be even be send to the tab? Do you mean the router sends it to the tab? And if so how? - by attaching supplementary data like a "port extension" stored in the NAT? which the browser attached initially? Could anyone explain?

[@pantelisvasileiadis2858]

thank you very much dude! very simply and well explained!

[@Certbros]

Thanks Pantelis! Appreciate it 😁

[@yashkummar]

Thanks for sharing. Well explained.

[@Certbros]

Your welcome

[@Jarrah_Kilgour]

Nice video, but I have a hole in my understanding.... if the router swaps the private address for a public address as shown, how does that solve the issue of there not being enough public addresses? surely some other router somewhere is using the same public address in it's "pool".

[@azran1180]

you are still replying, great and good video helped me for my assignments :)

[@Certbros]

I try to reply to all comments if I can. Glad you liked the video and good luck with the rest of your assignments.

[@vaishalivg]

Excellent explanations 🔥🔥🔥

[@TimonLevy]

Dude, this guy's voice is so calm I almost fell asleep watching this.

[@wexwexexort]

Best explanation I've seen so far.

[@Certbros]

Thanks Mert

[@jasonkittle326]

Mine has a lot going on. Thank you!

[@zi0]

Very well done lads.

[@Certbros]

Thanks Zi0!

[@TheAMOS45]

Amazing explanation . I got it on the first go

[@Certbros]

Thanks! Glad it helped you out.

[@ranjitdhiwar8545]

Nice Explanation . Thank you so much !

[@Certbros]

Thanks!

[@smellthecoffee5314]

Great vid - there should be more like this one - I like the way the facts about the process are cross referenced to their real world applications - A lot of IT vids miss this and you end up not really understanding where the info actually fits in the real world. Should have more views.

[@Certbros]

Actually! Real world examples help a lot

[@L84AD88]

Very nice vid made it easy to understand

[@utoobbott8817]

awesome explanation.

[@Scruibyxmontages]

Nice, feel like a genius now, really appreciated

[@Certbros]

Haha! You are a genius now!

[@Brooksiebaby1113]

Thank you for the explanations on the different types of NAT. The second edition of Information Security: The Complete Reference by Mark Rhodes-Ousley does not explain the concepts thoroughly enough for me. The sections of PAT,dynamic NAT, and static NAT were a little too brief. Your video broke it down just enough for me and the added visuals will help me to remember the particulars.

[@Certbros]

Happy to hear it helped and thank you for commenting. Good luck with your studies!

[@BijouBakson]

Thank you, that was pretty useful

[@jaelski1217]

I love you guys for this.

[@Certbros]

Love you too man! 👊

[@fleurazure]

Just wanted to say thanks for these very helpful videos! :)

[@Certbros]

You're welcome! Thanks for the comment.

[@azizbasitsheikh]

Very well explained

[@ayeshafatima266]

Great job 👍, please keep such wonderful videos coming. Thanks

[@Certbros]

Thank you Ayesha!

[@jeremyr8793]

Subscribed thanks for the vids! Keep it up!

[@Certbros]

+Jeremy Ruan Thanks! A new batch of video is on the way soon.

[@jagdishsingh5877]

smoothly DONE !!!

[@Certbros]

Thanks!!

[@Laith.Alkhazragy]

Thank you for the explanations

[@Certbros]

You're welcome. Thanks for the comment.

[@satyavir8]

Fantastic love ❤️ it man

[@zangreiner1048]

6 years since this video was published and i can confirm that it is still a great video

[@iftyomar]

Thank you very much for your lecture.

[@Certbros]

You're welcome! Thanks Omar

[@jdelarosa0325]

Thanks I learned a lot very well explained.

[@Certbros]

Thanks

[@marlymutos1000]

Thanks for the knowledge...

[@Randyorton98ful]

Thank you, this video is really helpful

[@Certbros]

You're welcome. Glad it helped 👍

[@Gisbert-12843]

Btw awesome explaining! Got an awesome voice!

[@tanvirhaider617]

thank you sir, you saved me a lot of time.

[@Certbros]

You're welcome!

[@Aman2111]

Thats the skill, How beautifully he explained NAT.

[@Uglyydidi]

Bro you a legend

[@subha517]

Hello sir...nice demo...one thing i would like to know if you could tell me...my question is by anyhow dynamic ip could be responsible for NAT TYPE 3 or strict

[@Throdne]

Loved the video! Do you think you can explain masquerade? Also, can you make a video just like this explaining firewall rules and how they work. E.g. like what’s the difference between related established invalid and new etc. I️ own a edge router, and I’m slowly trying to teach myself how to write firewall rules. Also, QoS would be awesome as well!!! Thank you, Throdne

[@Certbros]

Thanks Throdne! Masquerading is pretty much the Linux word for Overload/PAT in this video. I'm assuming your firewall is based on Linux so you likely have a SNAT (changes the source address) and DNAT (changes the destination address) option as well. Definitely going to do some security videos in the future!

[@sastyinkaroly]

You are the BEST!

[@user-ik6sk5wc5r]

Hello. Can you cover BGP, RIPv2 and distance vector protocols?

[@hassenbouchhiwa9827]

A question please: 3:55 the source port have to be above 49152 doesnt it ? to be dynamically assigned port number thanks

[@shakilalig]

As usual.. Certbros rocks!!!!

[@Certbros]

Thanks!!

[@ramprakashgovindaraj5343]

this is pretty much clear!! thank you for the video @certbros

[@Certbros]

Thanks!

[@margaritafemenias1635]

Awesome video! helped a loot!!

[@Certbros]

Thanks!!

[@SwissPhil02]

excellent explanations!

[@Certbros]

Thanks!

[@mikenerlyeustache]

What if I have multiple computers in private need to access to internet, as I have only one public IP from my ISP, how would be the NAT table? Thanks for your great explanation!

[@juice2090]

A pool is basically a really wide and flat bucket :D Great video

[@Certbros]

Yes it is! It's a deep and narrow pool! haha.

[@Munchkie]

I am curious, thx for explaining this :)

[@Certbros]

No problem! Glad you liked it!

[@mattwilson717]

As a new IT student I have no fucking clue what I just watched, but I’m sure I’ll come back to it

[@Certbros]

Sure this might be a bit much to start with. Come back when you ready.

[@markazer2501]

God bless you my friend :) very good class indeed.

[@Certbros]

Thanks!

[@davidbenson7323]

This was great. I would recommend updating the overall style of the video as far as graphics, but otherwise, I understand NAT now. Thanks CertBros!

[@Certbros]

Thanks. This is a bit of an old video now

[@dothchabani8565]

Hi ! Thank you ! I finally understood how NAT works :D Just one thing, Dynamic NAT is a many to many mapping addresses not a one to one, that's according to ICND1 documentation ^^' Keep going ! :D

[@lesleybw]

I realised he confused NAT and Dynamic too there!! Great video nonetheless, it really helped clear this out for me!

[@lesleybw]

Static*

[@oma_unashamed]

Thanks. Good explanation.

[@Certbros]

Thanks Oma

[@vladradu4148]

quality content, thank you!

[@Certbros]

Thank you Vlad! Glad you liked it.

[@prashantkamble2393]

excellent explainations

[@Certbros]

Thanks!

[@rockysheddy9227]

Please also upload PAT Port Forwarding Explained in details for this Cisco Router.

[@user-or7ji5hv8y]

Great explanation

[@Certbros]

Glad it was helpful!