Studying For Certifications

I’ve started studying for the CompTIA Linux+, and unfortunately I’m not making much progress. I’m kind of stuck on figuring out how I am going to study for it.

My old process that I used for the CCNA was to buy a study guide on Amazon and read through it and take paper notes. This ended up being a big waste of time. Paper notes are really hard to study from. I took paper notes on the entire CCNA book but I didn’t use them once for studying. Instead I created documents for each chapter on my computer. This worked pretty well but I ended up spending a lot of time struggling with the formatting in Calligra and libreOffice (MS Office is one of the few things I miss from my Windows days).

calligra_font[Calligra changes the font style seemingly at random]

The JNCIA was my first attempt to study based off of the published exam objectives. I broke the objectives into two massive documents, and slowly went through them filling out the information for each objective. This worked pretty well because Juniper had published two PDF study guides that followed the objectives pretty much in order. I was still struggling massively with Calligra. Unfortunately LibreOffice had a major bug where it wouldn’t open files from a network share so it was unusable as well.

Now I am working on the CompTIA Linux+ and unfortunately the study guide I have does not follow the exam objectives at all. I don’t want to spend a ton of time reading the book, only to end up with a bunch of useless notes. Instead I am going to make text files with the objectives, and then hunt through the book to fill in the details. That is going to be kind of a slow process, but it seems to be the best way to do it.

If I get another Juniper cert it is going to get even worse. As far as I can tell there  aren’t any study guides for the Juniper exams past the JNCIA. I have no idea how people study for them, other than just relying on work experience and crossing their fingers..

Juniper DHCP

I recently separated my wireless from the rest of my network by directly attaching it to my Juniper SRX210H and putting it in its own zone. That way I can make major network changes while still being able to listen to Pandora :)

The main change that I needed to make was to configure a DHCP server, and allow DHCP and DNS system services in the wireless zone.

The DHCP config is pretty straight forward:


Here’s the full list of setup tasks:

  1.  create a wireless vlan
  2. create a L3 interface for the vlan (
  3.  add the SRX interface to the vlan
  4. create a new zone for wireless
  5. add the physical interface and the L3 interface to the zone, and allow DHCP and DNS “system-services” through
  6. create a policy to allow traffic from the wireless zone out to the internet
  7.  create a source NAT rule for the new wireless zone
  8. setup the dhcp server
  9. check with the operational command:

> show system services dhcp binding

Circling back to the Linux+ Cert

Let’s take a time machine back to June 12th 2013. I had just completed the CompTIA Security+ Certification exam and had decided that the CompTIA Linux+ was going to be my next challenge. The Linux+ cert seemed like a good choice because I was really interested in Linux, and I needed more Linux stuff for my resume.


Fast forward a little to September 2013. I became aware of an upcoming opening in the network team at work and decided to switch focus from the Linux+ to the CCNA.

In the year between then and now I’ve managed to achieve both the CCNA and the JNCIA, and I got a firm start on a new career as a network tech in the process.

Lately I have been debating whether pursuing higher level vendor-specific networking certifications (CCNP, JNCIS-ENT) is worth the time and money. The network environment I support uses a large variety of vendors, and it is looking likely to get more diverse in the future. One constant is that most of the hardware runs Linux, and my home environment is all Linux.

I think it is time to start studying for the Linux+ cert again.

Learn C the Hard Way

I’ve decided it’s time to learn C.. The hard way!

I’ve played around with C++, Python, C#, and Java before, but C is different for me.

A big long term goal of mine is to get more involved in Linux, specifically in kernel or software development. The Linux Kernel is written in C, so learning C is a must.

In contrast to the other languages that I’ve worked with, I am going to try and learn C from the ground up. I’m be in the shell a lot, and I’m planning on using VIM instead of a more traditional IDE.

Learning C and getting more familiar with Linux will be complimentary to some of my other projects (OpenMarmot Switch in particular), but it might take the place of my Java work.

OpenMarmot Switch Hardware v1

OpenMarmot Annoucement Link

For my first build I am sticking with hardware that I already had in stock in order to keep costs to a minimal.


Here is the parts list:

  • Supermicro CSE-510T-200B Chassis (this is the standard model i use whenever possible because of the dual hotswap bays)
  • Supermicro D525 1.8Ghz Atom motherboard with dual Intel NICs
  • 4 GB of ram (2x 2GB dimms)
  • Quadport Intel NIC
  • Supermicro PCI-E riser card
  • 30 GB Crucial SSD

The Supermicro D525 systems have plenty of horsepower for small projects, and having dual NICs always comes in handy. I see them on ebay (with server chassis) for under $200 sometimes. I’ve used them as Windows domain controllers, PFSense routers, NAS/SAN, consoler servers, etc.. Every lab should have one or two.


Announcing OpenMarmot

Along with other big companies like Google and Facebook, Marmotsoft is announcing an in-house designed Linux-based network switch. Unlike other large companies Marmotsoft has also released a very nice logo to go with it:



So I’ve decided that I need a break from studying. It’s time to work on a fun project that will combine Linux and networking. I will also get to build some hardware (yay!!). I will be mostly working off other people’s tutorials for the software part, at least until I get a better grasp of the Linux network stack.


I passed the exam for the JNCIA a couple days ago, and so I am now a “Juniper Networks Certified Associate”.


The JNCIA isn’t just Juniper’s CCNA. It has a lot of topics that Cisco puts at the CCNP level, and it doesn’t spend very much time going over networking basics. Everything in it is pretty Juniper specific, it is basically a test of how well you can perform networking tasks using the JUNOS operating system.

I enjoy working on Juniper gear, and I may end following this cert up with one from the specialist track.

Marmotsoft Defined Deskworking


I think it is always really interesting looking at people’s personal work-spaces.

My current setup is designed so that I can work standing up or sitting down, and quickly move inbetween the two by dragging windows between my 23 inch monitors (the monitors are connected to the same workstation).

The biggest change from the last time that I posted this is I upgraded my 19inch (sitting) monitor to a 23″. I like 23″ monitors because it is enough room to have two windows open side by side while still having enough space to work on both of them easily.

The bottom shelf on the standing desk is great place to store the books that I am using. Currently it is holding my stack of O’Reilly Juniper JUNOS books and a couple other odds and ends.



Cumulus Networks

I read some articles about Cumulus Networks today. They make a Debian Linux based OS for bare metal switches.

I think it is really cool, but I don’t really understand what the target audience is. The big catch with Cumulus is that you have to maintain a software license ($500 a year for a 1Gb switch).

There is absolutely no way the company I work for would drop the extra cash for a software license (remember you still need to buy some sort of hardware RMA support for your switch).

I’d love to play around with it in the lab, but the cheapest hardware you can get currently is around $2500 + $500 for the software license. Nope- I’ll stay with my affordable and powerful Juniper EX2200 for now.

So yeah.. Definitely a cool concept, and definitely not aimed at cash strapped hospitals. The last thing anyone wants is more software licensing costs.


Thinking about this some more, I’m guessing the cost savings come in more in the 40/100 Gb fabric switch range than in your 1Gb access layer switches. I think there are also some benefits for centralized control. Plus Linux is cool. I just wish it was more affordable for the hobbyist. :)


Fedora 20 sound bug

Occasionally when I apply Fedora updates and reboot the sounds stops working. This also seems to occur sometimes when I restart while headphones are plugged in.

The fix is to open alsamixer (type alsamixer in the console), select the right audio channel and type “m” to unmute.

I found the solution for this on a Fedora forum, so it seems to be a known issue–but it has persisted for months. I can’t really blame anyone but myself of course. I’ve known about this issue for months, but I haven’t done anything to help track down and fix the bug.

Lately I have been feeling a bit overwhelmed by all the different stuff that I want to learn and keep up with, but I think that Linux is definitely something that I need to work on. A good start would be to try and help out with package maintenance and bug tracking.

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