Intermediate System to Intermediate System (IS-IS) Routing Protocol Fundamentals

[@conurm]

you saved my final project with this video, thank u a million

[@voynich7119]

IS-IS is now in the curriculum of the new CCNP Service Provider route. Unfortunately there aren't much ressources specifically for the SPCOR exam (at least as far as I know). So you kind of have to look for everything yourself. This was helpful for sure :)

[@diaphanoux]

I've always wondered if Cisco pretends that candidates are supposed to just take the plunge with the SPCOR exam and hope for the best. I think we can all agree that even if you're a networking Guru, you'll definitely stump into a few red herrings and mess up, probably even fail the exam.

[@msconfig9786]

personally i am taking the SPCOR exam in Aug 2023 CBT nuggets has a great Leacture type of explaination that helps better understand ISIS, He didnt really touch on the 00 which is the NSEL it is just like the TCP/UDP numer for ISIS it just tells ISIS what process to use. He didnt explain also the 11. before he added all those extra 1's to describe the Area nor the system ID or the NSAP addressing. Ik this was supposed to be a quick introduction to ISIS but i personally think breaking down ISIS addressing will help a lot of people when configuring it on the CML.

[@akshaybaishander4230]

can you please purpose of making network addressing like that?@@msconfig9786

[@the_stoned_investor]

I’m actually watching this because my company is getting ready to use it :)

[@AnikulapoOlawale]

Thank you so much sir. This is the first time I have seen the configuration anywhere. It is well explained and I get it. Thank you sir.

[@simons1992]

Very useful to watch this if you are gearing up for deploying SD-Access in your enterprise

[@ndeyanickche6369]

thanks, IS-IS has been made very easy to me through this video.

[@itsshowtime6412]

We WILL run into it, and it should even be in the CCNA imo (or at least CCNP Route) :)

[@mrfunnelz]

I just like this man's voice

[@mariomatejka]

IS-IS is part of CCDP. Used in the core of many ISPs, it could outlive EIRGP.

[@TruthNerds]

Beat me to it - by about a year. ^^ As a result of my work, I have access to the backbone topology of the main AS of a tier 1 ISP. They use IS-IS (and MPLS but AFAIK all MPLS routes are automatically configured based on IS-IS), and BGP of course. There are way over 1,000 level 2 (rsp. L1/L2) routers. I know of a smaller ISP AS that uses OSPF, but for the most part, ISPs seem to consider OSPF more of academic interest rsp. for smaller networks such as company site networks. There's the recommendation (again, IDK to what extent it's based on fact) to not use OSPF for more than 600 routers with interfaces in the same area, in particular the backbone (area 0). And I have yet to see a single ISP backbone using EIGRP. The main concerns are probably scalability once more, and potential vendor lock-in. (Note that the use of Dijkstra's algorithm is _very_ similar between OSPF and IS-IS, so it can't be the source of any scalability differences.) Besides, great intro and very accurate.

[@damaliamarsi2006]

I'm running ISIS in my network with all the same area and all l1/l2 routers (small network) so I can see all the routes. Also using a process ID (router isis 100) and of course have to do on the interface "ip router isis 100" but otherwise plan on splitting it up into different areas later. Definitely a fun protocol to play with and works great. Fantastic video that explains it well.

[@clcartlidge]

Studying for my CCDP - ISIS is mentioned quite alot thanks for this!

[@christianhiebl8501]

I discovered this the other day. If you configured Is-Is the same level 1 on both ends of interfaces and different areas it will turn it into a level 2. If it's same area then it will turn it to level 1. Just thought I'd share.

[@mr.hemsley1238]

Kevin thank you for the explanation you are amazing!

[@mesmeridze1]

Thank you Kevin, quick and useful.

[@ipforlife8918]

Many thanks for this explanation bro, just in 14 munits I understand IS-IS . You're the best

[@dg5109]

Thanks Kevin, great video as always!

[@akmbenoziralam3511]

Great ! Just learnt IS-IS basics in a few thanks sir .

[@alfortner6929]

Great Video. Practical and clear.

[@rahul_vasishtha]

thankyou, very clear understanding,

[@Oceanbig01]

thank you sir for this wonderful lecture on IS-IS. its been so help..

[@stefanosvirzi]

best explanation ever !

[@carlmaynewheeler]

thanks Kevin, great video as always!

[@Lee-qp2et]

This is my first interaction with ISIS and I like the video which gave me the first steps into this protocol. What's the point of using a /24 mask on a point-to-point link if you're not going to use the last octet number the same as the router number? After watching you configure R1, I decided to do the following router myself then watch the remaining video to see if I got it right. Apart from me using the last IP address octet to represent the router number which, when learning is so important when looking at the routing table as mine was a bit different from yours.

[@gbengaagunsoye1040]

This is so helpful. Thanks Kevin!

[@gatomas805]

I''m studying for my CISSP. In CISSP All-IN-ONE exam guide, it categorizes a IS-IS as a link-state protocol but you called a dynamic state protocol 0:38. Which is it?

[@kwallaceccie]

It’s a Link-State Routing Protocol, like OSPF. Enjoy your studies!

[@howardtur]

Thanks Kevin, clearly described in your video

[@georgiajaeger8567]

Thanks for the post, very helpful video Kevin.

[@Alestrix76]

Played around with this in GNS3 (admittedly using FRR and not iOS, but they're very similar) and initially couldn't get it to work. One thing I finally found out via trial-and-error: The level 2 router ID must be globally unique. It is not sufficient that the router ID is unique within its area.

[@Patmorgan235Us]

I would think you would want all router IDs to be globally unique. But that definitely makes sense that L2s must be sense they facilitate routing between areas

[@feedbrain6257]

Always high standard of training Sir:)

[@m-electronics5977]

14:10 can I make that Others way? That no default route would be advertised but only the networks?

[@raficnoureddine3979]

great lab thank you

[@faisalak7]

Thanks Sir

[@amruthvaranasi1691]

can you explain why in net command we used 11.11.1111 and so on?

[@amirahmed1404]

Thanks a lot Kevin. Great video 👍

[@sigilai89]

God sent. A big Thank you.

[@Taurus.x85]

Amazing as always

[@JN-ju6of]

Great video, thank you

[@aniessaboulsoof]

thank you very much

[@Harun1401]

Good Job! thanks

[@hhhhhh7406]

Thanks

[@alfredoboscabataller9899]

Awesome and well explained ISIS lesson!

[@raj_jaisur]

Hey Kevin, Great Video.

[@TheSathyam21]

Nice explaination.....

[@overtheedge107]

Thank you Kevin

[@Lee-qp2et]

R4 didn't get a default route but was able to ping R1, is this something to do with a newer ios. I'm using 15.6(2)T

[@helpeachotherall]

I am new to your channel , very Nice explanation.

[@colinleocanna]

Just what I was looking for. Been looking into Fabric path of late. Thanks so much Kevin.

[@shahidrashid6740]

Dear sir .can isis routing protocol using these days .plz tell us .i cannot see ccna ccnp s and mca mcsa syllabus

[@helpeachotherall]

Yes it is in use in few companies due to is-is is open protocol and easy. it used between cisco, juniper etc vendors

[@alexanderrudakov59]

great video!

[@AntonellaAngelini]

gives very significant insights! thanks :)

[@abdoulazizhassana5167]

Thank you!

[@c0tt0nm0ufh]

TYVM

[@kencheng2929]

Gold!

[@2004helloWorld]

video starts at 2:10

[@msizimthembu4332]

Very much appreciated. Stigma gone :)

[@arshidrashid598]

without seeing this video i can tell you rock in this video too.

[@tufuefiso2820]

best

[@karryw8695]

Best IP routing protocol was a protocol that was never designed (initially) to carry IP prefixes😆

[@GoonCity777]

Why do people always spell IS-IS and never just say it? Oh never mind.....I now remember.

[@closer-look]

STOP this RED BALL from moving UP and DOWN pleaseeees!!!