CompTIA CE

In 2007, I passed CompTIA’s A+ exams; that gave me a qualification which is valid for life. In April 2012, I enrolled in the CE (Continuing Education) program. In April 2015, I passed the Network+ exam, which gave me the Network+ ce qualification (valid for 3 years). Since I was within the deadline, I could also use this exam to get the A+ ce qualification, but that involved navigating CompTIA’s website: this blog post explains how to do it, since they haven’t made it obvious.

My main concern was that I’d cut it quite close with the timings. I took the Network+ exam on 2015-04-24, and the deadline for A+ ce was 2015-04-26. When I got the printed report after the Network+ exam, it said: “Please allow five business days for your CompTIA web record to be updated with exam results.” So, if the website didn’t process my results until after the deadline had passed, would I still be ok? Also, I took the exam on Friday and my deadline was Sunday, so I had less than 1 working day. However, it was all fine so if you’re in a similar situation then don’t worry about it.

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CWTS

Last month, I took the Certified Wireless Technology Specialist (CWTS) exam. This is issued by CWNP, who are similar to CompTIA, i.e. it’s a vendor-neutral exam rather than being based around specific technology (e.g. Cisco access points).

The CWNP website says: “The CWTS certification validates the knowledge of enterprise WLAN sales and support professionals who must be familiar and confident with the terminology and basic functionality of enterprise 802.11 wireless networks.” Similarly, when I booked the exam on the Pearson Vue website, they list it as: “PW0-071: Certified Wireless Technology Specialist – Sales (CWTS)”. This exam isn’t a pre-requisite for any of the higher qualifications, so you could start with the CWNA instead (“the foundation level enterprise Wi-Fi certification for the CWNP Program”). As I understand it, the main difference between the CWTS and the CWNA is “what vs. how”, although I don’t really know enough about the CWNA yet to comment in detail.

Having said that, I learnt a lot by preparing for this exam, and I think there is quite a bit of technical detail in here. For instance, here’s section 3.6 of the exam objectives:

Understand and apply basic RF antenna concepts

  • Passive Gain
  • Beamwidth
  • Simple diversity
  • Polarization

I think there are a lot of IT professionals who would struggle to define all of those terms. Similarly, here’s one of the sample questions from the start of the textbook:

What can contribute to voltage standing wave ratio (VSWR) in an IEEE 802.11g wireless LAN circuit?

  1. Output power of the access point
  2. Impedance mismatch
  3. Gain of an antenna
  4. Attenuation value of cable

So, this is a bit more involved than just saying “Buy a wireless router and plug it in at home”!

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Installing dd-wrt on a Linksys WRT320N wireless router

Back in 2011 I switched ISPs to A&A, primarily because they support native IPv6. Incidentally, 3 years on I see that you still can’t get IPv6 from Zen, so I made the right choice by switching.

Windows has had IPv6 support included by default since 2006 (i.e. Vista onwards), so the missing piece of the puzzle was my wireless router (a Linksys WRT320N). Unfortunately, the built-in firmware doesn’t support IPv6. (Source: Linksys devices that support IPv6.)

So, I investigated open source alternatives. There are a few different firmware projects out there, which all seem to be based on Linux. According to the OpenWRT wiki, it isn’t supported on the WRT320N. However, the WRT320N is listed in the dd-wrt router database, so I chose that instead. JP Hellemons wrote about this in 2010 (How I upgraded my Linksys WRT320N to DD-WRT v24); he also checked Tomato and HyperWRT, and neither of those were compatible. However, apparently the NoUSB edition of Tomato USB does support the WRT320N.

Update (2019-03-15): OpenWRT does now claim to support the WRT320N, although they don’t recommend it. Meanwhile, the Tomato USB website is now inactive, because the developer has ceased work on that distribution.

Just to forewarn anyone else who’s in a similar position, this isn’t a simple process. Here’s a good (valid) rant about how complex it is. I heard a good phrase a while ago: “Open source software is only free if your time is worthless.” I.e. if you assume that your time is valuable, consider how long it will take you to get a system working. Is it worth paying money to save yourself some time? For instance, in this case I could replace my router with a different model that has IPv6 support built in. (You will still need to invest some time in learning any system, but maybe you could reduce that from a day to an hour.)

In brief, I (eventually) got the router working fine with dd-wrt over IPv4. IPv6 took a bit longer; I’ve elaborated on that in another post (Native IPv6 in dd-wrt).

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CompTIA exams

Back in 2007, I passed the CompTIA A+ exams. Since then, there have been a few changes to the way these exams work. Unfortunately, CompTIA haven’t done a very good job of explaining it all; it makes volume licensing seem clear and simple by comparison!

In brief, if you currently have the A+, Network+, or Security+ qualification, you should enroll in the CE program. The deadline for enrollment is 31st December, so there’s not much time left. (If this applies to anyone you know, please pass this info on to them.)

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VDSL

I’ve recently swapped ISP, from Zen to Andrew & Arnold. More specifically, I had an ADSL line from Zen, and I now have a VDSL line from A&A; this uses FTTC (Fibre To The Cabinet), which BT have just deployed in my local exchange. I’m happy with the new service, and it’s definitely faster than what I had before: according to Broadband Speed Checker my download speed is 24368 Kbps, whereas it was about 3500 Kbps before. Unfortunately, the transfer didn’t go smoothly, and I wound up with no internet connection for eight days; I had to rely on my Orange mobile broadband dongle, which is roughly equivalent to dial-up speed. I’m not quite sure what went wrong, but there was definitely a failure to communicate somewhere along the line. If you’re considering a similar move, this post should give you an idea of what to expect.

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Protecting passwords

When I created accounts with Facebook and LinkedIn, both websites asked me for my email password to help me find people I know. The idea is that they can log into my email account, go through my address book, then search their own database for people with matching email addresses. That would certainly be convenient, and save me some time, but I think it’s a very bad idea.

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