OSPF Explained | Step by Step

19/09/2018 को प्रकाशित
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In this video we're going to take a look at OSPF.
Open Shortest Path First (OSPF) is a widely used and supported routing protocol.
It's an interior gateway protocol (IGP) meaning it been designed to be used within a single autonomous system. It also falls under the category of Link-state routing protocols.
Routers running OSPF learn about the enter network in order to create routes. They do this by flooding Link State Updates. There are three steps to the process.
Become neighbours - Two routers running OSPF on the same link agree to form a neighbour relationship
Exchange database information - The neighbouring routers swap their LSDB information with each other
Choose the best routes - Each router chooses the best routes to add to its routing table based on the learned LSDB information

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  • Hey waiting for MPLS video :)

  • I've watched about 3 videos regarding the same topic and this is the only video/animation that actually made sense. Great job at explaining a difficult topic in such a simple way! I'm impressed. Thank you!

  • This video was absolutely phenomenal! And the joke at the end was priceless.

  • Great video!

    • Thanks!

  • great video

    • Glad you enjoyed it

  • Rooter protocol 👍🏻

  • That's a very good explaination!!!

    • Thank you! Great to hear you liked the video.

  • ruthaaaaaaa jutha mutha futhaaaaaaa

  • Thank you!!!!!!

    • You're welcome!

  • Really nice explanation on OSPF , was straight forward and easy to understand

    • Thank you Michael!

  • It's pronounced router NOT router!

    • I think you'll find its router

  • Sooooo wonderful things realy its a pleasure to watching. This kind of vedios i wish you do more information like that .

    • Thank you! Great to hear you liked the video. More to come.

  • thanks very good just too many adds

    • Thanks for the feedback. Glad you like the video. I just let INplans place the ads.

  • By any chance can I get these slides please

    • Sorry, this video wasn't made with slides.

  • Old mac donald had a farm O - S - P ... wait wrong video

    • 🤣🤣🤣 this got me more than it should have!

  • 84 Dee arrs and Bee Dee arrs disliked this video... don't be a bee dee arr.

    • 🤣

  • Just remember ‘IT ELF’ > Init > Two-Way > Exstart > Exchange > Loading > Full

    • Great trick! Thanks.

  • At the very very first step you forgot to mention the acronym meaning of OSPF which I need to open another page and wasted another minutes of searching the acronym and typing this comment while you are profiting us. Hahaha

    • Oh my bad! It's in the description though 😀

  • really cool explanation for seniors

    • Thanks Javlon!

  • This might be old video but it really helped me understand what is OSPF... thank you.. I hope whatever names you mentioned are actual words used in real time. I watched the next vid as well.. multi area and its really good. I didnt understand EIGRP though... ill skip it for now. I was checking for BGP but i dont see that vid anywhere :/

    • @Jagadeesh Packet tracer is pretty simple once you get used to it. I need to make some tutorials myself. It's great your taking the feedback from your interview and learning this stuff. Good luck with the studies 👍

    • ​@CertBros thank you~..... I watched few other videos and happen to see people explaining in packet tracer.... that is when I found out there is a simulator that I can play with... Need to go through tutorials on how to use it... my last interviewer gave feedback that my knowledge on SDWAN is good but not much with n/wing concepts.... ill be stalking your channel btw~~ ^ ^

    • Thanks Jagadeesh! Glad you liked it. Keep going, you'll get there! Are you using packet tracer for labs? Its completely free.

    • @CertBros oo didnt expect reply as its old one~ i didnt understand that EIGRP calculations stuff... I wanted to get overview, watching couple of times would make me understand and need to compare with OSPF, then i can get better idea. However, since I dont have hands-on(as im learning using my imagination from watching videos and docs), its little hard to get those stuff. I am waiting for for the BGP vid though~ tnx for vid.. not just the explanation but the presentation is also good~ I could only be able to give the explanation without that such good presentation

    • Thanks Jagadeesh! Great to hear the videos helped! Which part of EIGRP did you struggle with? I don't have a BGP video yet but it's on my to-do list!

  • Great training

    • Thank you!

  • inplans.info/zone/Oj4mN2LbjZ28azX3D2OyKg

  • thanks man!

    • You're welcome!

  • Thank You - Great Break down of processes and explanation.

    • 🤣🤣

    • @CertBros There are about 78 people who do not want to continue Network careers.

    • Thanks Nadeem. I really appreciate it! 👌

  • I need the whole course of this

    • @CertBros ill check it out! thanks!

    • Hi Jay. I'm making a course now. Hopefully it wont be much longer. Check the description to register your interest 👍

  • on 5:28, when router 1 moves into a 2-WAY STATE, was it TRIGGERED by the fact that upon receiving router 2's hello, it sees itself as R2's neighbor?

    • That's exactly right 👌

  • The Cost you show in the video are old. please update it, IEEE changed it. @CertBros

    • @CertBros ohh right !

    • Are you thinking of STP not OSPF?


  • Best presentation I have come across. I dont know the regular use of rooter:)

    • CertBros you sound surprised 😀

    • 🤣 thanks. Good to hear you liked the video! Thanks for the comment.

  • How to choose the best path if the routers use the same type of interface? They have the same cost.

    • If two or more paths have the same cost, OSPF can load balance the traffic.

  • Brilliant. THANK YOU SO MUCH for this well illustrated video. love it and became a big fan.

    • Thanks Samir 👍 Really appreciate it!

  • so the guys here have a problem with "router" beeing pronounced in a way that it implies it is responsible for the fucing ROUTES? The fuc :D

    • 🤣🤣

  • very educative, if you love networking follow the link inplans.info/first/eqiop5-vrcCPgKc/v-iy

  • this video i benefited from it🙂

    • Glad to hear it 👍

  • It’s also what your car navigation uses 😀

    • Older models use RIP

  • solid ending lol

    • Thanks Jonas 🤣

  • Great video! Made me laugh at the end. I plan on getting my CCNA in the spring of next year. Thank you so much for helping on my journey to it.

    • @Brian Conner No, not yet!

    • Did you do it?

    • Thanks Chris! Good luck with your studies!

  • 12:03 but how does R1 know the cost for R4 to R5?

  • well explained.

    • Thank you!

  • what is this up status? 3.22

  • Thank you for the video. I would be great to see you guys explaining BGP too

  • Awesome video thanks so much :)

    • You're welcome!

  • That was good, I didn't understand all of it but I did get some of it :) I'm new to this yes.

    • You'll get it. Keep going 👍

  • Thank you very efficient for time and the amount of info!

    • Thanks!

  • This awesome do have a full playlist for ccna 200-301

    • Working on it now!

  • well maybe you would like to show me how to configure that in SSI instead of showing speed of the routes i could do this with one command

  • When does the LSA flooding happen?

  • Nice !! I would like to see videos about VRF, BVI, BGP too !

  • The master / slave selection, I thought priority was checked first then if a tie they go to router ID. Similar to the DR election? I guess assuming the default priority across all routers being enabled this would definitely be the case, but I have heard others claim this is how it is done, I personally am not sure. I would think you would want to control those values in practice to influence the elections the way you want them to be influenced, you know like what Democrats and the DNC have done these last few Primary elections with the collusion of CNN. At this point in my training we don't really get into master slave, so I am not sure how you would verify which router is which at this point, but when I lab later I will see if I can't figure that out. That's half the fun.

    • You're welcome! Happy the videos are helping. Keep labbing and using those debig commands! Haha! Dont worry, I'm British so I apologise a lot! 🤣

    • @CertBros TY for that quick response, I will check out that link as I am going very in depth on OSPF these next few days. Great video, helped fill in a lot of blanks and I am looking forward to the multi-area OSPF as I lab'd one last night and got a result I wasn't quite expecting and can't explain. I have a theory but I am not so sure it is correct. Again thanks. Yeah I am Canadian, I thank a lot.

    • Good question! The slave/master relationship is not that important for us to control. When you find conflicting information, the one place you can rely on is RFCs. They're massive but when you have a specific question they are a great resource. tools.ietf.org/html/rfc2328

  • OSPF explained in the best possible way.

    • Thanks!

  • OSPF works on which layer?

  • Why isn't Eirpg cost calculation designed like this?

  • Well DONE if you want to refresh what you know. Thank you

    • Thanks!

  • very good explanation wish you make videos for other topics too including ISIS MPLS etc.

    • More videos on the way

  • Awesome video, thanks CertBro! However, every time you say "rooter" my brain starts to wander away for a bit ..lol

    • Rooter rooter rooter rooter! Haha thanks Sarah

  • hahah "rooter". This just made a lot click for me !!

    • @GMN OMNICAST Aussie and we also say Rowter

    • @GMN OMNICAST pardon the interruption but us Yankees have been pronouncing it Rowter since we gain independence from the tyranny of Britain. Get with the times man.🤘

    • You must be a Yankee because we british pronounce Router as Rooter and not Rowter

  • nice explanation

  • Haha i did question myself about the rooter word LOL

  • Very well illustrated. Thanks mate

    • No problem!

  • YES YES YES Thank U!!!!

  • Well, this is a perfect background to see how dirty my monitor really is...

    • Beautifull animation. Can i know what is the software to build it? Thank you

    • Same here. That blue background came up and I said, "Oh yeah, I smashed a fruit fly there a month ago."

    • This color is also best for checking if monitor has dead pixel

  • I love his explanation on OSPF and Spanning tree protocol!

    • Thanks Birara!

  • Russia changed the OSPF priority to influence the election.

    • bah dum chhhh

  • a r-OW-ter is the one that will dig a hole in your hand. A r-OO-t is the one that's shaped like roots.

    • You must speak "American" and not "English"

  • Best explanation of OSPF

    • Thanks Rameez!

  • Yes best explanation on OSPF I've found.

    • Thanks Cam!

  • Thanks for clarifying this. Nice presentation also. 👍

    • Thanks Mehendra!

  • I root for you! 🙂

  • great explanation, do you videos for every topic for CCNA?

    • Thanks! More videos comming

  • Awesome. Keep doing more videos like this. Very informative.

    • Thanks Shijo. Working on more videos now

  • dude, you are awesome.....thanks for the clearly explained video.

    • You're welcome. Thanks Jaron!

  • great video hahaha the ending cracked me up hard bro. nothing I like more than smashing puss and learning my protocols dawg

    • Haha thanks!

  • 3 minutes in and I think the roota counter is already up to at least 50

  • Thanks for this. I think I dig OSPF. Fucking hate EIGRP though. Not your video, just the protocol ^_^

    • Haha thanks Michelle!

  • Nice

  • Nice video. If possible please also upload lecture on BGP protocol.

  • so simple and so clear thank you

    • No problem!

  • Thanks you

  • Great Explaination

  • Rooter a person that cleans out drains. Great job on the video one of the best.

    • Rooter is English, rowter is american-english

  • I though this "rootah" was fun only for me before i checked comments :D IN SOVIET RUSSIA WE SAY "RO - OO - T - E R"

  • Ya'll da truth.

  • guys website is not working

    • It's on the todo list

  • Love it love it love it

  • Love my cert broooo

  • you help me to pass my ccna, thank you so much

    • Awesome congrats! Welcome to the club!

  • very good explaination

  • Awesom video, in future if you are adding any no like part 1,2,3 then it would be easy for me to see the new uploaded videos one by one

  • very clear explanation... thx!!!

  • Enormously helpful - thankyou.

    • Thanks Paul

  • Wtf this video is in my recommendations 😂 nice info



  • It's pronounced "Routers!" Not "Rooters!" :) Great video :)

  • not sure if it was put to simplify it or put wrong. but when there is a change, the router which detected it tells only to DR, BDR (thru multicast) it does not flood the update to all

    • Multicast messages will be flooded but only devices listening for that address will process it.

  • Video was very explicit, thanks


  • super

  • Which book is best to learn networking

  • Thank you

  • Amazing way to explain OSPF step by step