Design considerations for network mergers and acquisitions

Network mergers and acquisitions are processes that can be seen in any type of business.

As network designers, our job is to identify the business requirements of both existing networks and the merged network and find the best possible technical solutions for the business.

There are many different areas that need to be analyzed carefully.

Wrong business requirement gathering and design analysis, definitely lead to catastrophic failures.

Business and network analysis and technical information gathering are the key steps and there are many questions that need to be asked and answered should be well understood.

Network mergers and acquisitions are also called Network integration.

Below are the key points for any type of network mergers and acquisitions projects.

Business analysis and information gathering

Applications of the company, at least the business-critical applications should be understood and analyzed very well.

What are the capabilities of these applications and what are the requirements from the existing network? (Packet loss, jitter, delay, application traffic flow, security and QoS requirements, and so on).

Basically in this step, we analyze the current infrastructure of the companies. IP addressing scheme, Application requirement, physical topology gathering, business future growth forecast analysis, security, QoS, Multicast, OAM and management infrastructure capabilities, and information should be gathered.

What type of WAN, LAN, and DC infrastructure each network is using, Is any VPN solution deployed on the WAN, is there a traffic engineering requirement on WAN or DC, and Is IPv6 supported by any of the companies? Is there any single point of failure and what will be the high availability requirement of the merged network?

What is the convergence time of the network and what is the required convergence time of any single component failure? (You shouldn't design the network for multiple failures)

As you can see there are so many questions that should be asked and noted during the business analysis. This is the most time-consuming step of any network design but definitely worth doing it properly to avoid any future problems and have the best network design.

Analyzing the design for network mergers and acquisitions is not different from analyzing the design for the greenfield network. Application and business requirement is always the most important, and technology is second. Alternative technologies always can be found.

Where will be the first place in the network for the merger?

When two networks merge, generally two networks are connected through their core network component. If there is any overlapping issue, for example, IP Address, these should be fixed. Traditionally IP address overlap issue is fixed via NAT (Network Address Translation).

Physical location selection is very important. As you will see later in the post, some of the sites can be decommissioned for operational cost savings. After deciding the locations which will be used, by extending the current WAN connections companies can start to reach each other.

What happens to the routing, IGP, and BGP?

Is a “ship in the night” approach suitable or redistribution is better for routing protocol mergers? One common routing protocol can run through both networks or if there are two different IGPs, redistribution can take place. If there is MPLS on the networks, any type of Inter-AS VPN solution can be deployed. In some Inter-AS MPLS solutions redistribution is not required.

Running common IGP is always better compared to dealing with redistribution. It is better for management, troubleshooting, convergence, availability, and for many other design objectives.

Which type of security infrastructure will merged network support?

What are the existing security policy and parameters of each individual network? You should deploy a common security policy for the merged network. You should make sure the edge of the network is as secure as possible and the core of the network just should transport the packets.

What are the Quality of Service Policies of the companies?

Will the final merged network support Quality of Service or through bandwidth everywhere? The quality of service policy of end-to-end networks should be deployed by understanding the applications of each individual company. That's why understanding the applications which were analyzing the network task, is crucial. You should follow the best current practices for QoS design.

Some businesses don't use QoS, especially on their core network. They generally have their DWDM infrastructure, so when they need extra capacity, they can provision it quickly and start using it. The reason why they don't use QoS is simplicity. They want to keep their core network as simple as possible. This approach is seen generally in the Service Provider business.

Will the merged network have IPv6?

IPv6 is unavoidable. There are many IPv6 business drivers for any type of business. If IPv6-only design is not possible for the merged company, at least IPv6 transition mechanisms should be understood very well and considered for the merged network.

Does one of the networks require Multicast? Will the merged network support Multicast?

If Multicast is running on any of the companies, most probably merged network will require and benefit from the multicast deployment as well. PIM (Protocol Independent Multicast) and current multicast best practices should be understood and deployed based on the company's requirements. Some applications of the company may benefit from the special Multicast routing protocol deployment model such as PIM ASM (Any source multicast), PIM SSM (Source-Specific Multicast), or PIM Bidir (Bidirectional Multicast).

What is the new capacity requirement of the merged network?

When two networks merge overall capacity requirement for edge and core networks generally changes. Understanding network capacity planning is key and network designers should understand the available methods for backbone and overall network capacity planning tools and best practices

How will be the merged network monitored?

Do exist Network Management tools capable to support all the technologies/protocols of both networks? Both companies may have different monitoring tools, application support might be different from their tools as well. Monitoring and management tools should be considered before the merger because tools should be able to support all applications, protocols, and technologies of the merged network.

When you divest the network, where will the data centers be?

Can you decommission any datacenter, POP location for cost optimization? Some of the locations of the companies may overlap and some POP locations and/or datacenters, even Head Quarters can be decommissioned to reduce operational expenses. The physical topology of the companies should be understood well and if there is a cost or advantage of choosing a particular location, definitely needs to be considered.

This is definitely not the entire list for network mergers and acquisitions, but you should at least start your design with these questions in your real-life design as well as in the design certification exams. In the CCDE exam, questions will be based on the above considerations mostly.

Further Study Resources on Network Mergers and Acquisitions

Network Mergers and Migrations book-Wiley

Network Integration Panel Discussion

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


Network Design Fundamentals Course

02:28:37 Hours
17 Lectures


Cisco CCIE Service Provider Training

108:43:00 Hours
258 Lectures