How TCP really works // Three-way handshake // TCP/IP Deep Dive

You need to learn TCP/IP. It's so much part of our life. Doesn't matter if you are studying for cybersecurity, or networking or something else. Learn TCP/IP.
// MENU //
00:00 ▶️ Intro
01:32 ▶️ The beginnings of TCP
03:57 ▶️ Three way handshake
07:20 ▶️ SYN meaning/explanation
08:50 ▶️ Port numbers
09:58 ▶️ What actually happens in the handshake
14:19 ▶️ Common starting TTL values
15:04 ▶️ Why we need SYN numbers
16:11 ▶️ What actually happens in the handshake (cont'd)
19:00 ▶️ Q&A (SYN,SYN-ACK,ACK - Sequence numbers - Increments - Tips)
33:01 ▶️ History of TCP
34:44 ▶️ TCP options
36:56 ▶️ TCP flags
41:53 ▶️ TCP Window - window size and scale
59:04 ▶️ MSS (Maximum Segment Size)
59:49 ▶️ SACK (Selective Acknowledgement)
01:00:13 ▶️ Conclusion
// PCAP File //
Wireshark TCP pcap file: www.dropbox.com/s/l5p8ofik86z...
// MY STUFF //
www.amazon.com/shop/davidbombal
// SOCIAL //
Discord: / discord
Twitter: / davidbombal
Instagram: / davidbombal
LinkedIn: / davidbombal
Facebook: / davidbombal.co
TikTok: / davidbombal
KZbin: / davidbombal
//CHRIS GREER //
LinkedIn: / cgreer
KZbin: / chrisgreer
Twitter: / packetpioneer
Pluralsight: TCP Analysis Course: davidbombal.wiki/tcpwireshark
// SPONSORS //
Interested in sponsoring my videos? Reach out to my team here: [e-mail]
wireshark
wireshark tcp
packet analysis
tcp
tcp/ip
ccna
ccnp
tcp handshake
tcp syn
tcp syn ack
ccie
tcp ip
cisco ccna
Please note that links listed may be affiliate links and provide me with a small percentage/kickback should you use them to purchase any of the items listed or recommended. Thank you for supporting me and this channel!
#wireshark #tcp #hacking

[@haphamdev]

I'm a software developer with a little networking background. Today I've learnt a lot more networking knowledge than my 5 years at the university. What a brilliant video. Thank you very much.

[@saucegotti8538]

sounds like you didn’t pay attention in university

[@HungNguyen-zx5zf]

@@saucegotti8538 not everyone could handle all knowledge (and remember them) from university until they get their hand dirty on real world, genius.

[@anonShrivastav]

​@@saucegotti8538😂

[@mwafulirwa1]

@@saucegotti8538 it depends on the university i thnk...my college sucked, had to learn almost 90% of the things i know now on my own

[@dbug7276]

😅😅😅😅😂😂😂😂🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣 Madman

[@Jarek.]

I couldn't believe that I would watch 1hr video on 3-way handshake and claim it was fascinating!

[@davidbombal]

Glad you enjoyed it! 😀

[@JeremysITLab]

Found my weekend watching! Great stuff, loving the details on TCP.

[@davidbombal]

Thanks Jeremy! Great to see you here again 😀

[@junaidjaved4792]

Jeremys IT lab sir 😍😍😍😍😍❤❤❤❤

[@nevarius9010]

The GOAT

[@aaqibshafiq5468]

Please add some topics :-dhcp/dns/arp

[@evanstayuka381]

Jeremy IT Lab, Sir your lessons are gold

[@CFH298]

Can you create a playlist containing all videos with Chris? This was so invaluable and combined with reading TCP/IP Guide it all makes sense. Thanks all!

[@davidbombal]

Here you go: kzbin.info/aero/PLhfrWIlLOoKO8522T1OAhR5Bb2mD6Qy_l

[@CFH298]

@@davidbombal You’re the best :)

[@SiddhantSwami]

@@davidbombal You are the best, David!!!!!!

[@AshleyEhSMR]

@James Great question! Appreciate you 🎊 And David wasted no time. The playlist I didn’t know I needed today ❤️🙌🫶

[@simplekindofman8867]

This is so incredibly thorough. Great job!!

[@thecuriousengineer]

This is the greatest TCP/IP lesson I have ever watched. Thank you both, David and Chris! :)

[@nuxboxen]

I have to say WOW... the way you two work together is just tremendous. This is really easy to listen to and really conducive to learning.

[@MSSMusChaos]

One full hour of knowledge, thank you Chris for giving a easy-to-follow introduction.

[@partspieces8165]

I'm loving these interviews with David & Chris. Really is valuable. 2 networking pros having a talk like a teacher & student scenario for us beginners to understand better & making it more engaging. Thanks so much!

[@phil2768]

When you can listen to something like this as a podcast (not watching), while working on something else (I was tidying up), and can understand everything that was talked about then you know that the person talking not only knows what they are talking about, inside and out, but can also explain and teach it clearly. That was excellent 👌🏻

[@ZeyRonTT]

I thought CCNA 200-301 had a lot of information about TCP ... Until I watched this video, thanks for a great video. Learned alot

[@educastellini]

-Great content professor David Bombal, and Chris Greer...!!! -Always nice when we look at the essentials in depth again. -TCP/IP, Three way handshake is the basis of almost all communication that we have in the network. -Great, this conversation and remembering in depth what we studied with the view of colleagues....!!! -Thanks for the knowledge teachers David Bombal, and Chris Greer...!!!

[@jean-ericrioux4726]

This is so well explained. I will use this video as a complement to the training I do internally to colleagues. I'm somewhat THE tcp and Wireshark guy at work, and often gets technical questions / request to troubleshoot something, even protocols I never worked with. Here's some things I really liked in this video: - When you mentionned to ''Please capture the TCP handshake''. You're so spot on ! It's just so critical to have - In TCP Options, MSS is not negociated but announced. (so many times I had to tell people this) - SACK has to be enabled and announced in both Syn and Syn Ack. Here are some suggestions of topic you could discuss in the future: - Same video with ICMP (explaining all the codes, etc) - A bit more depth on MSS (MSS vs MTU and fragmentation issues....just had one yesterday! :) ) - Get some packet loss captures and demonstrate where is the packet loss (example: If you see original packet + retransmission you can assume the loss is after the capture point, etc, etc) Great work !

[@CyberNancy]

I appreciate how David and Chris present the basics, while so much of the modern movement has forgotten these core elements.

[@confidential303]

you may say with confident most of people don't know this

[@webplethora]

Thank you David and Chris for this fanstastic session. These sessions are really empowering and the in-depth knowledge that is imparted through this video is enlightening. I am truly grateful for this. Once again, thank you David and Chris.

[@stuartwill1992]

This is fantastic content, hearing the real life context of this system TCP/IP and the deep dive into how it works is great!

[@kapilsonyt]

Been following Chris for long time and having watched his all TCP wireshark videos, it's glad to have you here digged deeper TCP again for us. Thanks David and Chris.

[@davidbombal]

Thank you and you're welcome!

[@ChrisGreer]

Thanks Kapil! Great to meet you.

[@davidbombal]

// MENU // 00:00 ▶ Intro 01:32 ▶ The beginnings of TCP 03:57 ▶ Three way handshake 07:20 ▶ SYN meaning/explanation 08:50 ▶ Port numbers 09:58 ▶ What actually happens in the handshake 14:19 ▶ Common starting TTL values 15:04 ▶ Why we need SYN numbers 16:11 ▶ What actually happens in the handshake (cont'd) 19:00 ▶ Q&A (SYN,SYN-ACK,ACK - Sequence numbers - Increments - Tips) 33:01 ▶ History of TCP 34:44 ▶ TCP options 36:56 ▶ TCP flags 41:53 ▶ TCP Window - window size and scale 59:04 ▶ MSS (Maximum Segment Size) 59:49 ▶ SACK (Selective Acknowledgement) 01:00:13 ▶ Conclusion // PCAP File // Wireshark TCP pcap file: www.dropbox.com/s/l5p8ofik86zeieh/TCP-Handshake_ChrisGreer.zip?dl=0 // MY STUFF // www.amazon.com/shop/davidbombal // SOCIAL // Discord: discord.com/invite/usKSyzb Twitter: twitter.com/davidbombal Instagram: instagram.com/davidbombal LinkedIn: www.linkedin.com/in/davidbombal Facebook: facebook.com/davidbombal.co TikTok: tiktok.com/@davidbombal KZbin: kzbin.info //CHRIS GREER // LinkedIn: www.linkedin.com/in/cgreer/ KZbin: kzbin.info Twitter: twitter.com/packetpioneer Pluralsight: TCP Analysis Course: davidbombal.wiki/tcpwireshark // SPONSORS // Interested in sponsoring my videos? Reach out to my team here: [e-mail] Please note that links listed may be affiliate links and provide me with a small percentage/kickback should you use them to purchase any of the items listed or recommended. Thank you for supporting me and this channel!

[@trentmcgrath9712]

EXCELLENT

[@joelhorensma8036]

David, are you really ex NSA or is it a media stunt?

[@TampaRedd]

What software was used to capture this podcast/video? I know it's not Zoom, appears to be full HD or better quality.

[@vicdan90]

@David Bombal Hello, We would like to listen about future of Data Sciencist ,plus their Job roles. Your Thoughts will be great to us who Interest and will invest their learning in this data scientist roles . Thanks since now on.

[@IMAND93]

It really shows how much Chris is more experienced with teaching. A great way of repeating the same thing in different ways until it makes sense. That's why I like your videos, guys. Overall very informative video, about Wireshark and TCP both.

[@greob]

Another GREAT video! Love this series and love Chris, such a great teacher. Would love to see more about QUIC and UDP as well.

[@jonathantx]

Thank you for making kind of knowledge available to everyone. This really makes a difference when your new and starting to put things together in your mind and breaking out doing tasks on your own in a production network.

[@teomcam]

Wow what an episode. I can’t think of a word to thank you both enough for the treasure you giving us.

[@drumaddict89]

about 5 minutes in and LOVE how he describes and teaches stuff. thanks for your videos david! always a pleasure to expand my horizon with your content

[@sureshjoshi5933]

You guys are incredible! I've been looking for videos like this for a long time. Attaching the pcap file is a great idea so that person can follow along with your flow!

[@klwthe3rd]

Unlike the John Hammond video, this content is extremely valuable. Chris is an expert in the networking/packet analysis field and did a beautiful job breaking down these concept so one learning Wireshark gets the most out of the data packets and software. You need to create a play list just with Chris, having all his topics under one place. This just might be the single best educational video on the 3 way handshake on KZbin. I would like to see common problems/solutions that occur often in the real world where Chris would be called out for diagnosis.

[@bsparky01]

I know this is a two month old video, but I just wanted to thank you and Chris for putting this information out there. I have learned a lot from watching Chris' Wireshark videos, but this has been very educational as to why I am seeing what I see in the captures. I am not a network engineer/admin, but I end up spending a lot of time at work having to analyze network traffic because the application I support for my company is very latency sensitive and videos like these help me speak a common language with network folks to help get to the root of a complications. Thanks again for this and I am eager to dive into more!

[@dravidianChief]

1hr well spent. Thank you guys. Definitely need a series. Nailed the basics of TCP/IP. Thank you!

[@deenarshahid]

It's been amazing experience watching two of you explaining TCP basics in wonderful way. Would like to see you both covering TLS as well. Fingers crossed 🤞

[@samratchapagain4804]

Loving the way he explains the TCP like the real world examples. Eager to wait for another episode like problem of window scale size and many more. Thanks david and chris :)

[@shannon1573]

Thank you! Thank you! Thank you, David and Chris! I'm currently taking a college TCP/IP course & I think I've learned more in the last hour than I have in the last month! Our textbook is the TCP/IP Illustrated (2012) & although I I'm blown away by the technical details, I barely understand any of it. I also spend an ungodly amount of time researching what's still relevant. I've used Wireshark many times, but this video helped me UNDERSTAND it. TCP/IP is a prerequisite for my future Firewalls/Network security, OS Security & Routers classes, so I'm grateful for these videos to help me learn such a daunting subject. Please keep this series going!

[@juanrebella2589]

Absolutely amazing masterclass. Thank you Chris and David, superb material. Juan.

[@ricardow1130]

Just started studying for my eJPT and holy smokes did this video add value to what I've just learned. Can't wait for more in depth!

[@wiltonwell]

Thank you Chris and David you took me on learning trip with, there all the way. I have learnt from the best and you deserve more than I can give you both. I will continue watching your content, for me achieve my goal. It is people like you that are unsung heros of people for me that is trying my best to get there.

[@JudgeGideon823]

Love this practical knowledge. I am convinced, or rather confident that my career will be significantly more enjoyable and valuable if I understand Networking like you gentlemen. Like anything we don't know, it can be confusing and challenging, but once we pass those hurdles it's incredibly satisfying and worthwhile. Thank you David for what you do and for introducing us to some great people and professionals. Absolutely invaluable stuff here.

[@KhurramSSiddiqui]

I opened this video a couple of days ago and finally came to watch it over the weekend. Great video, awesome presenters!

[@samanthamorris3453]

Thanks for the video! In my professional life, one of the things that has really distinguished my more senior colleagues is their ability to understand TCP/UDP flows during troubleshooting. This video really helped me get an idea of what their brains may be thinking when we troubleshoot together! This is a video I'll watch multiple times.

[@ok-jq1jh]

THANK YOU! Finally what I've been seeing in tcp packets makes much more sense thanks to you guys. I do appreciate it, definitely love the deep dives keep it up!

[@ausafahmad8335]

Hey David, This video was just awesome. I am currently studying medicine but I've always been interested in computers. Once I'm done with med school I'm going to start with a computer science course and your videos keep my interest ignited. Thanks a lot !

[@CrashLoopBackOff-K8s]

Adding a comment and like for the algorithm. I also subscribed to Chris. Great conversation and examples. More of this, please. As a reminder, your audience not only includes those just beginning their networking careers, but also those like myself who are professionals in other areas and need to pick up enough skills to be competent in some of the areas you focus on. Your content is appreciated, David.

[@ged4440]

David and Chris, this is fantastic. I have watched so many presenters to learn this stuff and Chris, you are amazing in the way you teach it!

[@samahhabib18300]

i watched the video on pluralsight explaining the tcp, and i think this is the most simplified explanation, the questions from David make the difference. and expiations from Chris were great. thank you all.

[@Zerback]

Thank you very much for going at this level. You are helping a lot of people that just starting on the networking/ security side of computers. Please continue going deep with different types of protocols!

[@jm-nn4fz]

Cris and David you are real educators and no starch material on this channel 👌

[@kevinlong3147]

Thank you so much David and Chris, this was very eloquently taught. I had a better time understanding here than my ccna classes.

[@willd9807]

This is the most valuable video i have found on youtube or anywhere regarding packet sending. The only way it could be extended more is how the actual wire (or photo optic) is transferred from point to point. This video is priceless and belongs in Universities as a compulsory IT or Comp Sci must watch

[@erezcohenbox]

Thank you for letting me listen to your conversation! I have learned a lot. Great job.

[@arorarachit]

hey david, awesome stuff. cant wait for this we need the continuation of this series!!

[@jacobhenriksen2324]

Absolutely LOVE this! Can't wait for the rest of the series!

[@dhughes19962009]

I took a course that walked me through tcp among other things, but i didnt understand the importance and utility of it till watching this video. I very much appreciate the knowledge. Thank you both for your generosity in sharing with us all.

[@andriejusartamonovas1857]

so simple, so clearly explained, yet so hard to digest... I guess I've found something I will enjoy grinding on! thank you!

[@chillarn7]

Amazing video, learned a lot! It really helps seeing the packet captures to fully grasp the TCP concepts.

[@kshitijpatil4145]

Thanks for the series David & Chris this deep dive session is really amazing, took 1 hour of my time but would love to utilize more than that for future deep dive episodes as it is really interesting to learn. Considering TCP would like to learn examples with TCP flags RST, PSH, URG also if we use NAT & PAT how the other TCP header info will affect for the actual source & destination systems.

[@shokijames]

Chris you explained everything so good that I went straight to your channel and subscribed. Thanks to both of you

[@wasid7678]

you never disappoint your students David neither with your tutorials nor with your guests .. Keep doing this awesome work _V_

[@mikkio5371]

i have to come back and watch this . nice Chris . practically explained

[@Sherloklol]

This was some of the best tcp/wireshark education i've seen where you simply things so it's understood. well done and thank you

[@tomsgrinbergs8020]

You definitely got to continue with this type of content, cheers Chris for this. Really good bunch of notes I've made on my side!!

[@briteness9356]

That "Packet Head" T-shirt is awesome!

[@JMalikZ]

Never seen someone dissect TCP handshake like this. Amazing!

[@robertwoodson227]

One of the best videos I have seen. Beautifully explained

[@samhull8028]

Spot on, there is so much info to take in, will need a few repeats, but loved the indepth walkthrough, really helps to understand. Chris's enthusiam is brilliant, you kept the pace managable, like slowing to 10base from Chris's 1000base. lol thanks

[@noevaz]

I saw this video a few months ago and I struggle a lot to understand, after reading some material and practicing I watched the video again and I really understand more about TCP, definitely you need to spend time and be PATIENT when learning this topics, great video David and Chris!

[@mystay88]

Thanks a lot for that video. Those kind of deep dive videos ares my preferred. Flow is perfect. Bravo! Catch you guys on the next one.

[@chfstudio]

Wow! Very clear and powerful explanation! Thank you for this lesson!

[@tylerroman6065]

Absolutely loved the video! I'm currently doing research on Multi-path TCP so its amazing to have better understanding of TCP! Thank you!

[@powellthepog5624]

The explanation for the sequence number (raw) was a life saver!

[@ajaykhanna1981]

Awesome Stuff, so insightful !! Thanks Chris and David. I loved the way David keeps on countering Chris and Chris very calmly and brilliantly knocking it out of the park.

[@rakeshcristobal8320]

Great detailed look into TCP with Chris! Looking forward to more videos with Chris!

[@tomhartley5086]

Awesome video David and Chris, your collaborative videos are awesome and very helpful!! MORE PLEASE :)

[@SantoshBansodeSB]

Dude this is best explanation i ever got, I appreciate your work.

[@oscardotel3787]

this is the most beautiful video i’ve ever run into on youtube. wow. thank you thank you thank you

[@Shalom_Mike]

Wow! Great video for non-network admins too. 😃 Can't wait for more! The subject matter was explained perfectly! Even I understood it!

[@deivids4221]

What an amazing video. Thank you to both and I hope there will be more to come. This is very well explained and put together.

[@madusankasampathweerasingh8570]

I cannot believe that I watched the whole video without skipping! Superb explanation!

[@Bharath-wb8uy]

Thank you buddy I love all your episodes and thank you for creating a playlist with all of Chris's videos

[@andydufresne9387]

The best network guide I've ever seen!

[@Johno3998]

Man, the concept of "splitting the OSI model in half" to troubleshoot is such a good one, I've never thought of that

[@oumadahmed4625]

Just discovered your channel and I’m so happy I did. Your work is a masterpiece

[@StanleyLoh]

as a dual CCIE i still find this very useful and informative. recommended it to everyone in my team.

[@Addy580]

This really made my 1 hour journey back to home from office fun, thanks 🙏

[@gtsui87]

Absolutely love this content. Most content that are on the web that pertains to tcp are explained in a very complex way. I love how Chris makes this very dumb down for the average person looking to learn tcp. Please continue this series as its very interesting and provides invaluable knowledge.

[@ChrisGreer]

I try to explain the way my brain processes things - so I gotta keep it simple! :-)

[@jindalabhishek1]

Hey David and Chris, Thanks for sharing and giving back to the Community!!!. I will follow your path and share as much as I can

[@nahleaky586]

This was a great overview of the TCP/IP part of a networking class I took in university. Well done!

[@meinetub]

One of the best series on the channel

[@sunilkalekar4677]

Great to see a colabration video with 2 experts form the world of network.

[@cryptoknight5927]

Thanks a lot for both you two David and Chris that's what we really want as it's a simplifying the heavy manual books information and move many student from beginner level to the top

[@robertprice7459]

Brilliant explanation by Chris, big thank you to Chris and David. Can't wait for the next instalment

[@chandramohanr2000]

This is a great session!! Got a lot of insights around the TCP. Thanks David for arranging this session!!

[@mrmike81818]

Found a little gem with this video and I've never seen such a breakdown. Wireshark seems so much simpler now. I'm looking forward to taking networking to the next level with you guys, thanks!

[@anilbhushan349]

Absolutely helpful. Yes, please keep this series going.

[@tonyhoy4688]

An hour very well spent. Thanks chaps.

[@Jason.Detrick]

I'm studying for my CCNA and I need all the help and insight I can get for each of the layers of the OSI / TCP model. Learning about the handshake and the behind the scenes down into the raw numbers and why the packets are what they are and how each client frames up the numbers is great, so thank you! I'd love as much real life troubleshooting as I can get, down to why each possible problem might end up showing itself. It can be overwhelming for sure and just reading about it can be so dry it's hard to hold the knowledge but with video examples like this I believe it will help a lot.

[@maheshsudarsi82]

many training institutes are not not teaching these underlying concepts. Great work and thank you...

[@Casperr123]

Brilliant, great refresher of TCP. Fantastic teaching and explanation skills at both ends of the connection.

[@themistoclesnelson2163]

Enjoyed the deep dive. Came for the window, but watched the whole thing.

[@ricksanchez9669]

That was awesome! The best tcp explanation ive ever seen hands down.

[@Vikasadhangale]

Another great video on Networking and TCP, thanks David and Chris!! Would love to see the playlist of this entire series with Chris :-)

[@aliabbas48]

Can't tell how much I love it. David, please keep the deep dives up !

[@davidbombal]

Thank you Ali!

[@pallavi8388]

Thank you David, this is soo interesting and informative. Finally i got to know what happens in 3way handshake. Until now i just thought SYN SYN ACK ACK. Chris explains everything in such a detailed manner just love his explanation.

[@dustcore]

Brilliant video, thank you both. I'd like a little more detail on how these window sizes work with MTU.

[@charlesikpeme7777]

Thanks David, the networking world is better because of you. Thanks for mentoring millions of people.

[@davidbombal]

Thank you Charles!