cwap

CTS 060: Road to CWNE

The journey to CWNE is not a straight path. It takes preparation, determination, and patience with a lot of studying. This is my summary to CWNE #210.

CWNE LogoDeciding to tackle the CWNP certifications towards CWNE is a task you do not take on lightly. In 2015, I had decided to create a personal goal of fulfilling my Wi-Fi dreams of becoming CWNE. While the certifications were not required for my job at my employer I was wanting to complete them for myself and to have the credibility of a CWNE.

In December 2016, I received the confirmation email of becoming CWNE #210 and was filled with a lot of joy from the sweat from the hard work.

CWNA

The CWNA cemented a foundation in Wi-Fi and proved there was much to learn in this space.

I used the CWNA study guide from Sybex which helped me pass the exam the first time. The book covered all the topics and provided more information beyond the scope of the exam.

During this time, I had also begun doing a Wi-Fi podcast to help me stay on track by constantly talking about the topic. The Clear To Send podcast has definitely helped me stay focused on Wi-Fi topics. I believe that teaching others is a way to also help yourself really understand the technology.

My CWNE Timeline

 

My timeline for CWNP to CWNE

CWNE Requirements

The requirements for becoming CWNE are straightforward and outlined on the application PDF.

CWNE requirements as of January 2017:

  • You must pass CWNA, CWAP, CWDP, and CWSP and they must be current.
  • Have three years of experience (verifiable) Wi-Fi administration, Security, Protocol Analysis, and Quality of Service
  • Have three endorsers
  • Meet listed achievements such as a published book, white paper, recorded instructional presentation, updated blog, etc
  • Write three essays (each over 500 words but not longer than 1000 words) which speak to your knowledge in Wi-Fi

  • Hold two valid non-CWNP certifications

CWAP

After completing CWNA, the next task is figuring out which professional level certification to go with next. My recommendation is to knock on CWAP. The analysis portion will arm you with the knowledge to pass the other exams with a little more ease. Analysis requires you to know more about design and security which is why I recommend this path. Within the CWAP you will dive into the frames and know more about frames than you ever wanted to.

When I first started tackling CWAP, I had tried to rush myself into passing before CWNP made the exam changes. Rushing is definitely a recipe for failure as I didn’t pass on my first attempt. What made things worse is that I couldn’t review fast enough for a second attempt before the exam changes.

Without giving up, I ended up purchasing the CWAP Study Guide by CWNP. While the book was much thinner, it did contain enough information to pass the exam.

I highly recommend capturing many wireless frames to help solidify the topics for CWAP. I lived and breathed in Wireshark during my CWAP. Anytime I needed to troubleshoot a Wi-Fi issue I always opened Wireshark just to see what was going on.

Something I always remember was when I solved a slow Wi-Fi issue due to a client constantly sending out CTS-to-Self frames with large duration values. I wouldn’t have seen this if I hadn’t gone through CWAP and applied what I learned.

CWDP

My decision to go with CWDP next had to do with the work I was doing with my employer. At the time I was doing quite a bit of design work so it was only natural that I took this path.

When I looked into book resources for learning CWDP I learned the book for the previous exam version was much bigger than the new version by CWNP. I decided to pick up both for the purposes of learning more.

The CWNP book is what I used to study for the CWDP and the previous version, by Sybex, I use as reference.

CWSP

I left the CWSP as the final professional level certification to tackle. This was in part of security being one of my weaker areas.

After reviewing the objectives I knew there would be quite a lot of terms to be familiar with. One of those being 802.1X and the security methods.

When you study for the CWSP be sure you know each of the authentication and encryption methods. Know what the difference is between them and which ones should and should not be used. What helped me learn the topics really quickly was building a Wi-Fi lab and experimenting with each method.

At home I have an Intel NUC which has VMware ESXi installed. I deployed a FreeRADIUS server and learned how to setup 802.1X with different access points and with a Cisco WLAN controller. Then during the authentication process of a device I would capture the wireless frames and analyze them.

If you take this route you will remember the topics much easier.

CWNE Application

In parallel to my CWSP studies I began working on my CWNE application. Why do it in parallel? It made it faster to apply after passing the last required exam.

The easiest task to do here is find three endorsers who can attest to your knowledge in Wi-Fi.

My three endorsers were:

  • Colleague
  • Manager
  • A CWNE

I recommend you at least find one CWNE to endorse you. You should really find a CWNE to guide you through this process when you are early on into your CWNP studies. I’ll talk more about this later.

Experience

A requirement of the CWNE is having the experience. Get exposed to working on Wi-Fi networks in areas of administration, design, analysis, and security. You may even be able to volunteer your expertise to non-profits who do not have the funds or capacity to do Wi-Fi networks properly. Look out for Episode 61 on this topic.

If you haven’t already, start a blog talking about your Wi-Fi experience. Talk about the subject as if you were teaching someone. You can see some examples on my own blog.

Other ways to get experience is to have published Wi-Fi articles. I have a few on Network Computing.

If you have questions about whether something is eligible you can contact CWNP and get verification.

Essays

You’re required to write three essays that show your knowledge in Wi-Fi. A simple way to approach this is to look at the three professional level certifications. You can write three topics on Design, Analysis, and Security.

I don’t recommend writing three essays on the same topic. For example,  you write three essays all on Design. That only speaks to your design knowledge.

You will want to show that you’ve been able to learn from the CWNP certifications and have applied that on a project or in the workplace.

Reach out to a CWNE and ask for guidance. You may even want them to review your essays to provide any input and recommendations for improvement.

Mentors

Early on in my Wi-Fi career I had indirect mentors. What I mean is I followed some of industry experts by reading their blogs, listening to their podcasts, and engaging with them on social media.

What I wish I had done when I first started was actually reach out to specific individuals and ask them to become mentors. These are CWNE’s who have the time to provide guidance to someone starting out in the CWNP path.

First you must be a good mentee. I always always always emphasis on doing the research first. Try to find the answers to your questions. And then when you have hit that wall you can approach your mentor with the results you found and ask for the push towards the right direction. A mentor will never give you a straight up answer. They are there to guide you.

A good mentor will be someone who is approachable and has the time (many CWNE’s are very busy with work travel and family). They provide guidance, input, recommendations, and experience. A mentor does not give you all the answers. They will encourage you along the path and push you to do better.

I want to thank one person specifically who has guided me throughout my CWNE journey and that is Francois Verges. He was patient with me, reviewed my essays and provided valuable input. Thanks Francois!

Resources Used During CWNE Journey

CWNA

CWAP

CWDP

CWSP

Applications

Hardware

Blogs

CTS 053: 3 Simple Tips for Passing the CWAP Exam

These 3 simple tips for passing the CWAP exam may seem easier said than done. Listen to the podcast to hear more details about each tip and how I used them to pass the CWAP exam.

Certified Wireless Analysis Professional In September 2016 I sat and passed CWNP’s CWAP-402 exam. The exam costs about $225 as of this episode. It’s a multiple choice exam consisting of 60 questions which you need to complete in 120 minutes. The CWAP is the analysis portion of CWNP’s set of certifications.

So let’s go into my 3 tips for passing the CWAP exam:

1. Read The Book Twice

I’ve opted to read the Kindle version of this book. For over a year now I’ve gone completely digital with my books. It works well with my workflow and I hate carrying around heavy books.

The content is very technical so it helps to read through it multiple times in order for the topic to sink in.

My schedule consisted of reading one chapter a week. That was my goal. Some chapters can get very long so it helped to break them out over a couple of days. Pace yourself with each chapter and don’t rush it.

Take advantage of the chapter quizzes. If you score 80% or better, move on to the next chapter. Scored less? Then you need to review. Don’t read the answers for the quizzes. Doing so will make you memorize the answer for the chapter quiz.

2. Take Good Notes

I use Evernote to capture all my notes. You can use other similar apps such as OneNote, Google Keep, or even paper and pencil.

Review each of your notes every day. This will keep the content fresh in your mind. Key things you’ll want to note down are various frame exchanges such as associations and security. Knowing what’s inside of these frames is crucial too, such as what’s inside a beacon frame.

Note down the differences between each PHY and you’ll start to see why that is important.

Another topic I highly recommend knowing is QoS parameters and their priorities.

These little details are good to note down and will be beneficial in your passing.

3. Lab Up Scenarios

A big part of my success if being able to see a lot of Wi-Fi in action. Protocol and Spectrum analysis is a big part of the exam.

I started off by installing Wireshark and using Airtool (Mac app) to capture frames. I got familiar with frame exchanges and what was contained in those frames. I looked at various beacons, associations, and security frame exchanges.

For spectrum analysis I used Metageek’s Chanalyzer. The CWAP book uses Air Magnet. The interfaces differ between Chanalyzer and Air Magnet.

It will be important to spot the different characteristics of interference such as microwave, video transmitters, Bluetooth, and other 802.11 traffic.

Aside from those three tips, experience is a big plus. Having come across many of these topics will help you pass the exam. One such example is troubleshooting wired side issues.

The CWAP exam actually puts some emphasis on the wired side of things because they often mask themselves as Wi-Fi issues. So you have to know how to troubleshoot an issue using the CWAP methodology.

Things I did not take in preparation for this exam:

  • Practice exam
  • Bootcamp

I felt I prepared enough that I didn’t have to take either the practice exam or bootcamp. I’m not even a fan of doing either. For my CWNA I did take a bootcamp and found it beneficial. I guess at the point I was studying (for both old and new exam) I just got tired of studying and decided to jump into the exam.

CTS 046: CWAP-402 Study Guide Released

Hey what’s up everyone. In today’s episode we talk about TP-Link discovering what it’s like to ignore DFS, Google Fiber going Wireless?, Data frame slicing with Airtool, and CWAP exam gets updated and so does the study guide.

TP-Link Settles $200k with FCC for ignoring DFS and power limits

FCC reaches settlement of $200k with TP-Link for selling Wifi routers that ignore DFS requirements and power limits. This sounds very careless for a networking company. Is this what we accept now as hardware from these companies. Maybe TP-Link thought they could get away from it, or maybe an engineer wasn’t aware of the FCC regulations. But is this what we expect with inexpensive hardware? I don’t think so. Along with the fine, TP-Link has agreed to work with the open-source community to allow consumers to install third-party firmware on TP-Link routers.

This is a good move in my opinion but unprecedented from the FCC. This is a great way to move our wireless industry into embracing open-source.

Google Plans to Extend Fiber Into Wireless

CFO, Ruth Porat, said that Google Fiber would be exploring wireless due to the acquisition of Webpass. This was mentioned in Alphabet’s 2nd quarter earnings call. Why in the world would Google Fiber go into wireless? The main obvious reason I can think of is cost. It’s much cheaper to use hardware that costs a fraction of the cost of digging up fiber. Not to mention the labor costs of doing the work.

I think this is an interesting turn of events as Google Fiber now becomes fiber over the air. I can see the marketing lingo now….

Latest Airtool Update Gives Us Data Frame Slicing

Airtool is one of my favorite apps on OSX. It allows me to capture wireless frames using my built-in wireless adapter. But in doing so, some of these captures can take up precious hard disk space.

What Adrian Granados has done is enabled a feature to just grab the beginning of the frame and discarding the rest. What you have left is the 802.11 MAC headers.

Check out the latest update.

CWAP-402 Exam Released

The latest update to CWAP from CWNP is CWAP-402. It is 90 minutes and contains 60 questions. It is available now to test and has been available since June 28 2016.

Certified Wireless Analysis Professional

CWAP-402 brings changes to 5 subject areas.

Tom Carpenter has hinted that Troubleshooting is a big part of the exam from the CWAP update webinar.

These are the objectives.

5% – Troubleshooting Processes
25% – 802.11 Communications
15% – WLAN hardware
35% – Protocol and Spectrum Analysis
20% – Troubleshooting Common Problems

Troubleshooting processes is a very small chunk of the exam at 5%.

Focuses on a troubleshooting methodology. Mentions of industry and vendor recommended processes. Not sure how vendor neutral this sounds.
But with any troubleshooting process, OSI Model is mentioned. Just remember that Wireless is at the Data Link and Physical Layer.
May mention of Wireshark and Omnipeek as well as the tools baked into OS such as command line using ping and traceroute.

At 25% is 802.11 Communications.

This sounds like the MAC Layer Frame Formats and Technologies AND 802.11 Operation and Frame Exchanges from the previous exam. Looking at 802.11 communications from a troubleshooting perspective. Understand the frame exchanges when a device tries to join a BSS. Getting as detailed as finding out why a device would fail to join a BSS. Learn the different frame formats – management, control, and data. Learn the PHY header and preamble and why a device would have issues on a BSS because of the header and preamble.

15% is WLAN hardware.

Troubleshooting client devices and their issues connecting to wifi which includes dealing with drivers, security settings, and other configuration settings available on different drivers. There’s troubleshooting via protocol analysis using a tool such as wireshark. Do you know how to set up that application and look at wireless frames. There’s troubleshooting the spectrum using a spectrum analyzer. Do you know how to identify common interference sources. Other troubleshooting aspects include why APs can’t power up so we’re looking at PoE.

35% for Protocol and Spectrum Analysis.

Beginning with the basics of hardware and software protocol analysis, features of protocol analyzers, how to install and configure them, capture traffic and analyze them. On the spectrum analyzer side, again going over hardware and software spectrum analyzers, terminology that is used amongst different spectrum analyzers, features included in applications such as Spectrum XT and Chanalyzer, creating reports from your findings, and how spectrum analyzers integrate with your wifi adapter. Of course you should know how to use a spectrum analyzer by finding different forms of interference.

20% reserved for Troubleshooting Common Problems

This one is new for the CWAP. An obvious focus on troubleshooting. It may sound funny on a wireless analysis exam but you will need to know some wired issues with DNS, DHCP, switch configurations and WLAN controller access. These issues relate to services wireless clients use. Other common issues tackled are co-channel and adjacent channel interference, noise, hidden nodes, and more.

Just reading through the objectives it sounds like this may be an easier exam than the previous version but we’ll see how people react. Version 2 objectives are a lot more shorter than the previous.

CWNP Releases New CWAP Material

With the latest revision of the CWAP exam now comes the latest study guide. The author is Tom Carpenter of CWNP. The technical review is Lee Badman who I interviewed on the podcast back on Episode 13.

It’s available on Amazon in print and on Kindle. If you’d like to support the podcast, you can purchase this book on Amazon.

There’s a total of 8 chapters:

  • Troubleshooting Processes
  • 802.11 Communications
  • 802.11 Frames
  • WLAN Hardware
  • Protocol Analysis
  • Spectrum Analysis
  • Wired Issues
  • Common WLAN Issues

It would be beneficial to do a lot of packet captures with wireshark to help follow along with the book and get hands on. If you can, get ahold of a spectrum analyzer as well.

I use the Metageek Chanalyzer with the dBx dual-band adapter. Another popular spectrum analyzer that can be used alongside this study guide is AirMagnet Spectrum XT.

CTS 042: Interframe Spaces

Interframe spaces play an important role in 802.11 medium contention. They are used as additional medium contention protocols in addition to CCA and NAV. An interframe space, or IFS, is a quiet period access points and stations must wait before transmitting a frame.

There are shorter interframe spaces used for higher priority data transmissions. Think about QoS in that regard.

There are four rules that define which IFS will be used before frame transmission:

  • If arbitration is complete, then reduced IFS (RIFS) or short IFS (SIFS) will be used.
  • If arbitration has not been determined, then arbitration IFS (AIFS) or DCF IFS (DIFS) will be used. DIFS is used for 802.11 WLANs that don’t support 802.11e QoS.
  • If AP or station received a corrupted frame, then extended IFS (EIFS) will be used.
  • PCF IFS (PIFS) is part of PCF and not used in the real world.

AIFS

DCF Access Category Windows

EDCA

Links and Resources Mentioned