Two weeks ago, I wrote a blog post on how to prepare for Aruba ACCX certification. I got some positive feedback and interest from many of my contacts who asked me to write a post on how to prepare for ACMX and ACDX. Last week, I wrote a blog post on “How to Prepare for ACMX” and this post will complete this series and cover How to Prepare for ACDX!
As you know, Aruba offers multiple certification tracks for different technologies like Mobility, Design, ClearPass and Switching. ACDX is the expert level certification in the design track that really confirms your technical expertise in designing large-scale solutions based on Aruba technologies including wireless, wired and location based services. It is a comprehensive exam tailored for Presales Engineers who want to validate their expertise in designing solutions based on various Aruba technologies including Wireless, Wired, ClearPass, Network Management and location-based services. To be very transparent, I didn’t sit for the latest lab exam but I did the exam when it was based on earlier versions and I passed from the first attempt. Later on, I renewed my ACDXv8 by passing the written exam.
I am sharing my view on how I would tackle this exam. As always, I think about any certification as a journey and the knowledge that is acquired which preparing for the certification is the most important aspect.
ACDX EXAM – BRIEF OVERVIEW
To attain the ACDX certification, candidates must pass the Aruba Certified Design Expert (ACDX) written exam prior to attempting the ACDX lab exam. You can check the details for ACDX certification here. I will focus on preparing for practical exam here but the readings will be very useful for both the written and practical exam.
As shown below, 55% of the exam is based on IRIS, 30% on Essay Questions (justifying / clarifying the design choice), and 15% on Airwave Visual RF. Don’t be fooled by this distribution, the focus is not on testing if you know how to use IRIS only, but rather testing you on choosing the best solutions to meet the design requirements. IRIS and Visual RF/Ekahau are just tools to help you in the design.
RECOMMENDED TRAINING & STUDY RESOURCES
For me, the most important part in preparing for ACDX is having an “Architect mindset” and working in designing Aruba solutions. You need to go from understanding the requirements and challenges to designing a cost effective solution that meets these requirements and challenges. You should be confident in defending your design in front of the customer and for your implementation team who will deploy it later.
The recommended resource to prepare for this exam is the Aruba Advanced Network Design and Solutions official training course. It is indeed a very comprehensive course and it will be very helpful resource both to pass the exam and for your day-to-day work as a pre-sales engineer covering Aruba technologies.
As part of your preparations, I would recommend you read many documents from Aruba like the ones mentioned below. Many of the contents of this course are from materials in these documents.
- AOS 8 Fundamentals Guide – The name says it all! The focus should be on understanding how to design a large scale setup. Don’t focus on the configuration aspect but focus on the high level picture:
- What are the controller modes? What is the role of the MM?
- How do we achieve redundancy for APs? Controllers? MMs?
- What licenses are needed to enable a particular feature? VIA? Multizone? WIPS?
- How do we size the solution based on AOS 8? How to size MM? MD?
- How do we secure the solution? What policies are usually commonly used in various roles?
- How do we design for Guest services?
- Layer 2 vs Layer 3 design?
- IAP VRD and RAP Solution Guide – IAP and RAP are part of the exam and it is essential to understand how to design the networks based on these components. Things to think about while preparing include:
- When to consider controller vs controller-less?
- What is the scale for controller-less?
- How will the IAPs be managed? When to choose Airwave? When to choose Central? Which licenses are needed with these platforms?
- How to handle a global deployment of RAPs? Regulatory domains?
- Mobile First Campus & Aruba Campus for Midsize Networks & Aruba Campus for Large Networks – Remember the exam is not wireless only, it is a complete end-to-end solution design including wired. Make sure you read these documents and focus on
- How to select the right switch model for access? distribution? core?
- 2 Tier vs 3 Tier Architecture?
- Over-subscription calculations?
- Understanding traffic patterns and when to have dedicated aggregation layer for wireless?
- How to select the right switch? Stacking Requirements? POE requirements? Connectivity Requirements (SFPs? SFP+? QSFP..etc.?)
- Management Solution for Wired Network?
- How to leverage wired ports on APs in hotels or dorms and reduce your switching footprint?
- Advanced Wireless Design – I would recommend you check
- Aruba Very High Density VRD – The name says it all.
- I would recommend you check AB424: Outdoor WLAN Design: Simplify Outdoor Deployments & AB426: Warehouse Wi-Fi Design: Tips for Design and Deployment in Any Space sessions on ATM digital covering key outdoor topics (I know these might be based on newer models but the concepts are the same). You might as well check older outdoor VRDs.
- ClearPass – Make sure you are very familiar with ClearPass solution sizing
- How to choose ClearPass appliance?
- What is the role of Access license? Onboard? OnGuard? How are they licensed?
- How to size the solution
- What are the roles of the Publisher, Backup Publisher and Subscribers?
- Meridian – Make sure you are very familiar with Meridian deployments and focus on
- How to size Meridian solution
- What is needed for Asset Tracking? Way-finding? Push notifications? Bluedot?
- Make sure you are familiar with the licenses
- Wireless Design – A key component of the exam is to design the wireless network to meet a particular set of requirements. Things that you should be familiar with include
- Coverage vs Capacity Planning?
- Channel Planning?
- Designing for Roaming?
- Meeting Throughput Requirements
- Designing for Air Monitors
- IRIS – Yes, you should be vary familiar with IRIS. It is the main tool that you will use to design the solution and build the BoM! Make sure you are familiar with this tool and understand the various support options that are available and how to choose them.
While taking the exam, try to be systematic and use your time wisely. The exam is very demanding so time management is key. Try to highlight the requirements to make sure you have them covered in your design. In the essay questions, make sure you provide the answer without wasting so much time on a particular question.
Hopefully, you will pass the exam and attain your ACDX #. It is a tough exam covering various Aruba technologies but it will definitely give you a wider knowledge in Aruba portfolio that help you in your pre-sales career. Let me know your feedback and if you need any technical clarifications.
(Note I will not discuss anything related to the exam itself due to NDA but I can help you if you need any technical clarification)