BGP - Why does BGP require an IGP to function?

Рет қаралды 2,566

Күн бұрын

One of the prerequisites to deploying BGP is the fact that you need to have fully functioning routing within an Autonomous System before you can deploy BGP. In other words, in order for internal BGP (iBGP) to operate, you must deploy an Interior Gateway Protocol (IGP) such as EIGRP or OSPF to ensure routing is established. This however can be counterintuitive. Since we're deploying BGP, which is itself a routing protocol, why do we need another routing protocol to make it work? In this video, I'll explain the reasoning behind this seemingly illogical logic.
Chapters:
==============================================
00:00 Introduction
00:53 Routing Must Be Established within an AS
02:44 Understanding the Role of BGP
04:39 Hierarchical Approach
05:18 Summary
Related links and videos:
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What is BGP? - • BGP - What is it?
eBGP vs. iBGP - • BGP - eBGP vs iBGP - W...
#bgp #igp #routingprotocol #deployingBGP #lazarusagapidis

Пікірлер: 34

@Rigel_Kuriom_Mandara Ай бұрын

Probably one of the best presenter here!!! ❤❤

@Lazarus.telecomTech Ай бұрын

Really? Thanks so much!!

@tristennewman9917 2 ай бұрын

Thank you Lazarus! very helpful and truly sounding simple, much appreciated

@Lazarus.telecomTech Ай бұрын

Hello! I'm glad it is helpful!

@mhewett5193 2 ай бұрын

This video series has helped simplify BGP immensely. Thank you for the effort!

@Lazarus.telecomTech 2 ай бұрын

I'm so glad it has been helpful! It's messages like this that make it all worth it...

@majiddehbi9186 2 ай бұрын

first time u a great teatcher buddy

@Lazarus.telecomTech 2 ай бұрын

Thanks so much!

@frenfinder3622 2 ай бұрын

Great and clear video!

@Lazarus.telecomTech 2 ай бұрын

Glad you liked it!

@danpacheco1 5 ай бұрын

Good video. To more simply answer, why to we need an IGB to make BGP work? The IGP allows reachability to all other BGP peer routers in the AS. This is a prerequisite to establish a BGP session and send/receive BGP updates in the full mesh

@Lazarus.telecomTech 5 ай бұрын

Absolutely! Thanks for your contribution, it's always helpful!

@bustamantesuarezanthony7478 5 ай бұрын

What is the point of using iBGP then? could I not just run OSPF(for instance) and redistribute my routes learned by eBGP to OSPF and vice versa? what is the real advantage of using iBGP? it seems to me just extra work, because after all, the AD of iBGP is bigger than IGPs. Hope you guys can respond.

@ahmad82pkn 4 ай бұрын

If you have routes coming from multiple EBGP peer then if you use IBGP then you can control traffic with BGP Attributes(which si easier). But if you just do redistribution then you can only choose path based on OSPF Cost as preferred path. So you get less flexibility . Secondly. Now you will have to do reverse OSPF to BGP redistribution as well. Which create more challenges and possible loop. So with IBGP it natively take cares of that route advertisement both ways with single protocol.@@bustamantesuarezanthony7478

@hanisirfan 2 ай бұрын

@@bustamantesuarezanthony7478 From the little knowledge that I have, all the IGP protocols are designed to handle small amount of prefixes and have a faster convergence than BGP. Meanwhile BGP are designed to carry large number of prefixes (100 thousands or even millions) and have slower convergence time. Why did we prefer to have slower convergence for exterior protocols? It's because the amount of prefixes it need to carry and updates to the peers. Well, Internet routes changes are not that often when comparing route changes internally within an AS. Correct me if I'm wrong.

@JobbsAdegede 2 ай бұрын

@@bustamantesuarezanthony7478 I have often asked the same question, have never understood thepoint of IBGP

@srb1855 4 ай бұрын

Excellent!👍

@Lazarus.telecomTech 4 ай бұрын

Thank you! Cheers!

@richardurassa9261 10 ай бұрын

Nice one Laza

@Lazarus.telecomTech 10 ай бұрын

Thanks Richard!

@arindambhattacharjee1476 3 ай бұрын

Excellent

@Lazarus.telecomTech 3 ай бұрын

Thank you! Cheers!

@a354681 4 ай бұрын

Thank you Sir.

@Lazarus.telecomTech 4 ай бұрын

You're very welcome! 🙂

@arindambhattacharjee1476 3 ай бұрын

Nice sir..

@Lazarus.telecomTech 3 ай бұрын

Keep watching!

@norah8493 9 ай бұрын

Thanks, you answer my Qs

@Lazarus.telecomTech 9 ай бұрын

Happy to help!!

@williebrown4266 6 ай бұрын

WTF is a rooter?

@Lazarus.telecomTech 6 ай бұрын

Ha! I was sure this would come up at some point. The word "route" can be pronounced as "raout" or as "root." For example, when you say "Route 66" you pronounce it as "Root 66" and not "Raout 66." Although it is true that the more prevalent pronunciation, when it comes to routes and routers in networking is "raout" and "raouter". However, this is primarily an American pronunciation. UK and international English tend to use the "root" and "rooter" pronunciations more. So I choose to use that pronunciation. It's a matter of personal choice, but thanks for giving me the opportunity to address it... 😉

@williebrown4266 6 ай бұрын

@@Lazarus.telecomTech Mr. Lazarus, I must apologize as I was just being a bit facetious with my glib comment. You are exactly right, outside of the US you will most likely hear it pronounced "rooter". The first time I actually heard it I was working with some guys from Telkom South Africa and they referred to it as such and we had no idea what they were talking about. Your BGP videos are excellent by the way. Informative, short and to the point. I'm a subscriber and will continue watching.

@Lazarus.telecomTech 6 ай бұрын

@williebrown4266 no need to apologize, but thanks for your friendly message!

@fmurphy92 3 ай бұрын

Can't watch this when you're purposely ignoring the correct pronunciation of router just to be different

@Lazarus.telecomTech 3 ай бұрын

Hello @fmurphy92! I understand, and I am really sorry that it's distracting. Just to be clear, I'm not doing it just to be different. The pronunciation "root-er" is a legitimate correct pronunciation of the word in UK and International English. (A quick Google search will confirm this). The pronunciation “raou-ter”, which is also correct, is an American pronunciation. I am Canadian, which typically has a mix of American and UK influences for spellings and pronunciations. So for me, route and router are pronounced as “root” and “rooter”. (For example, even in the USA, you would pronounce Route 66 as "Root" 66, not "Raout" 66 right?) Some Canadians tend to use the American pronunciation and that’s fine too! To each his own. I hope you can look past my pronunciation and still find the videos useful… :D