BGP Route Reflector vs Confederation

BGP Route Reflector - RR vs Confederation is one of the first things Network Engineers would like to understand when they learn both of these Internal BGP scalability mechanisms. For those who don't know the basics of these mechanisms, please read BGP Route Reflector in Plain English and BGP Confederation Blog posts from the website first.


BGP Route Reflector vs BGP Confederation

There are many differences when we compare Confederation vs Route Reflector and in this post, some of the items in the comparison chart will be explained.  


BGP Route Reflector vs Confederation Scalability

Both of these techniques are used in Internal BGP for scalability purposes. But BGP RR changes the Full Mesh IBGP topologies to the Hub and Spoke. BGP confederation divides the Autonomous System into the sub-ASes but inside every Sub-AS, IBGP rules are applied. Inside BGP Sub Autonomous System, full Mesh IBGP or Route Reflector is used.

So, we consider BGP RR compare to Confederation to be more scalable because inside Sub-AS still full-mesh IBGP might be used. If RR inside Sub-AS is deployed, then configuration complexity would increase.


BGP Route Reflector vs Confederation Loop Prevention

BGP Route Reflector in order to prevent the routing loop uses two BGP attributes. Originator-ID and Cluster List. Originator ID is basically if BGP RR sees its own Router ID in the BGP update, it will not accept the update so routing won't form.

Luster list is, when the route passes through the routers, revert router adds its Cluster-ID into the Cluster list, if same Cluster-ID update comes, BGP update is not accepted, thus routing loop is prevented.


Using Different IGP in BGP Route Reflector and Confederation

BGP RR is used in a single BGP AS. Inside single BGP AS, usually single IGP is used. But this is not the hard rule. In theory, there can be multiple IGP protocols in different parts of the network for internal prefixes and customer prefixes, or Internet prefixes still can be carried within BGP.

But in practice, as said above, single BGP AS and single IGP routing protocol designs are much more common in real-life networks. But the BGP confederation is almost always the opposite. BGP Confederation is seen in real life because of Mergers and Acquisitions. The companies before the merger and acquisition might be using different IGP protocols and usually, they continue to use different IGP protocols.

The reason they continue to use different IGP protocols is, that their network engineers get familiar with the protocol over years, operatinally and design-wise, thus it doesn't make sense to have a common IGP and push the engineers to learn whichever that IGP. Although in the above list and in general there might be many more comparison points between BGP RR vs Confederation, for this post hopefully it is enough and was useful for our readers.

Created by
Orhan Ergun

Orhan Ergun, CCIE/CCDE Trainer, Author of Many Networking Books, Network Design Advisor, and Cisco Champion 2019/2020/2021

He created OrhanErgun.Net 10 years ago and has been serving the IT industry with his renowned and awarded training.

Wrote many books, mostly on Network Design, joined many IETF RFCs, gave Public talks at many Forums, and mentored thousands of his students.  

Today, with his carefully selected instructors, OrhanErgun.Net is providing IT courses to tens of thousands of IT engineers. 

View profile

Daniel Lardeux
Daniel Lardeux Senior Network Consultant at Post Telecom

I passed the CCDE Practical exam and Orhan’s CCDE course was very important contributor to my success. I attended the CCDE course of Orhan Ergun in July and it was exactly what I needed, Orhan is taking the pain to break down the different technologies.

Roy Lexmond
Roy Lexmond Senior Network Designer at Routz CCDE #20150017 & CCIE R&S; #26557

After I attended Orhan Ergun’s CCDE course I passed the CCDE practical exam.I really enjoyed the course a lot ...

Nicholas Russo
Nicholas Russo Network Consulting Engineer (CCDE/CCIEx2), Cisc

I signed up for Orhan’s CCDE training. This training is very technically detailed and the use-cases, quizzes, scenarios, and mind maps are all great resources in the overall training program. Orhan teaches his students to think like a network designer ...

Slide Heading
Slide Heading Network Systems Engineer at Conscia A/S CCIE #42544 (SP) & CCDE #20160015

Orhan is forcing you to take off the implementation hat that most of us have been wearing for many years, instead he is providing a new fancy design hat, which makes you see and deal with the issues presented ...

Kim Pedersen
Kim Pedersen CCIE in RS and SP (#29189) CCDE#20170021

I’ve used Orhan’s self-paced CCDE training material. If you are interested in knowing how all the technologies go together in a coherent design i can highly recommend it.I also enjoyed the Quizzes which helped pick out my weak spots in selecting ...

Laurent Metzger
Laurent Metzger 3xCCIE/CCDE Senior Network Architect

Hi Orhan. I passed the CCDE exam on February 22. I read everything that you put on your Self Paced CCDE Training course and it was very helpful in my success. Thank you very much.

Martin J. Duggan
Martin J. Duggan Network Architect at AT&T;, Ciscopress Author CCDE #20160006 & CCIE#7942

I attended Orhan’s April 201610 days CCDE Bootcamp. I am CCDE now !

You can tell Orhan has a great deal of experience, it really comes through when he presents his design case studies and the CCDE Practical scenarios.

Muhammad Abubakar
Muhammad Abubakar Lead Network Architect – CCDE #20160016 2xCCIE #26693 2xJNCIE VCIX

Your excellent CCDE materials and amazing Bootcamp helped me tremendously through my learning journey.Also thank you very much for being available whenever I have a design question or a complex design topics. I can’t compare your design skills ...

Jennifer Pai
Jennifer Pai Network/Security Engineer at KNET Technology

Thanks Orhan very much for this course. It helped strengthen my “Network design mind”.

Ruslan Silyayev
Ruslan Silyayev Solution Architect at R.I.S.K Company

Training by Orhan is not a CCDE preperation training only. It will be useful for engineers which are dealing with design. You want to pass CCDE exam or learn network design, then don’t look at anywhere else!

Sameer Meher
Sameer Meher Solutions Architect at 23 Wards/Japan

Orhan Ergun’s CCDE course was really very good. CCDE Level Intelligence was delivered very well and with very useful case studies and the scenarios, I am thankful to Orhan for all his help!

Ken Young
Ken Young Senior Technical Architect Province of Nova Scotia, 2xCCIE #41597 | CCDE #20170047

If anyone wants to understand network design and architecture, also pass CCDE exam , I recommend you to attend Orhan’s online courses! I am a CCDE now but learning is a journey, we will be together in your other courses too Orhan!

Matt Cross
Matt Cross Technical Architect at Heartland – CCDE #2019::7

Orhan did an excellent job of filling in the gaps of knowledge that I had that took me to the finish line of the practical exam CCDE. The community of people that Orhan facilitates are both engaging and supportive of the journey to CCDE. Orhan ...

Shiling Ding
Shiling Ding Sentinel Technologies – CCDE #2019::12

Just passed the CCDE Practical exam! I attended Orhan Ergun’s CCDE training program , used Orhan’s Instructor Led and Self-Paced CCDE training and Online CCDE Practical Scenarios during my CCDE journey. Orhan’s CCDE In Depth book is an excellent summary ...

Abelardo Basurto
Abelardo Basurto Solutions Architect at Cisco Systems – CCDE 2018::6

Hi everyone, I’ve just passed the CCDE Exam. My Number is CCDE 2018::6 I attended to Online CCDE Bootcamp of Orhan. I want to thank Orhan not only for the great book and bootcamp, but also for his commitment, availability and willingness to assist the ...

Hady Mohamed Abdellah
Hady Mohamed Abdellah Network Architect Hamad International Airport Qatar – CCDE 2018::1

Hi guys, I’m so happy that I passed the exam. I’ve already got my number CCDE 2018::1. Thanks to Orhan for being the best CCDE instructor in the world. I highly recomend Orhan’s CCDE Training and In-Depth-CCDE ...

Bryan Bartik
Bryan Bartik Sr. Systems Engineer at CompuNet – CCDE 20170059

Hi Orhan I passed CCDE Practical exam on November 2017 ! I really enjoyed your materials and quizzes and use cases. They were definitely helpful in my preparation. Thanks a lot !

Giedrius Trapkauskas
Giedrius Trapkauskas Network Solutions Architect at Liberty Global – CCDE 20180004

I attended Orhan’s CCDE Training in Istanbul and it was very helpful in my preparation. I passed the exam recently and I want to say Thank you Orhan! For those who want to pass the CCDE exam, definitely start with ...

Alaa Issa
Alaa Issa Sr.Solutions Architect – CCDE#20180033 3xCCIE ( Collab|DC|Security )#27146

I registered to Orhan’s training in Feb 2017. From that time, I attended Orhan’s training several times. The depth of knowledge which Orhan has is amazing, and how to present such consistent knowledge to the ...

Mazin Ahsan Design Lead Engineer | Solutions Engineer | CCDE License # 20160030 | CCIE Licence # 23892

I passed the CCDE Practical Lab exam on November 17,2016 from supplications of elders and dedication from my Sensei Mr. Orhan Ergun I took different CCDE bootcamps in the past. Orhan has the most depth and expertise ...

Jeff Patterson CCDE# 2018::11

Hi Orhan I wanted to pass along my appreciation for the outstanding training material. I used the online CCDE training provided by Orhan as well as the In-Depth-CCDE book and passed the exam in February 2018. Thank you Orhan!

Mehdi Sfar
Mehdi Sfar Network and Security Architect / CCDE #20210003 | CCIE R&S; #51583

I signed up for Orhan’s CCDE Self paced Course. This course, along with the CCDE In Depth book, helped me for my CCDE Practical as well as Written exams. It pushed me to ask the "WHY" questions and allowed ...

Related courses

Cisco CCDE v3 Training

71:39:34 Hours
225 Lectures
Expert

$995

BGP Training

22:46:48 Hours
22 Lectures
Intermediate

$150

Cisco CCIE Service Provider Training

108:43:00 Hours
258 Lectures
Expert

$995