Category Archives: BrainDeadTip

Wireless Networking in the Developing World

Greg Sowell had a great link this week in his blog — such a great link that I’m passing it along here.

This is an impressive piece of work.

The book is freely available for download and covers a wide range of wireless topics – including using Solar Energy for power, OLSR for routing, and low-cost tools (including the WiSpy) that can assist in site surveys.

So far I’ve only had a chance to skim the work, but I’m definitely impressed. Now I have some weekend reading to look forward to.

CCNA certified

Well, it took me long enough to get my ass in gear to do it – but I finally got around to taking the CCNA – and passed on the first attempt.

I’d been planning on doing so for as far back as my last few years in commercial radio, but a level of uncertainty (“What exactly is ON the exam?”) led to my procrastination.

Eventually I came upon the non-credit offering brochure of my local community college, and found they offered a class on what one needs to know and study to pass the CCNA.

The course was fast paced and had an impressive instructor (smart, rarely drifted off topic, had good studying suggestions, and a pretty good sense of humor). It also included a number of materials: Lab manuals, Cisco Certified Network Associate Study Guide (ISBN: 0470110082) by Todd Lamlee, and copies of RouterSim Network Visualizer 6.0 and CertSim. (There was plenty of hands-on lab time as well, including two Saturday workshops).

The  Network Visualizer software  is nice when away from the classroom lab – although I quickly found that I preferred using my home lab instead (something I’d pieced together via ebay over time).

A 2950, 2 1751's, a 26xx (and 2 2900's not pictured)

The home lab consists of a random number of bits: 2 1751’s with T1 CSU/DSU’s (got at a price of $39.00 together off Ebay), a 26xx ($60.00 off Ebay), 2 Cisco 2900XL’s (appx $70 together from Ebay), a 2950XL (about $80.00 off Ebay), 2 Quagga routers, an ImageStream Rebel Router, and a server dedicated to virtual servers (which I used to emulate 7204’s via Dynamips). Yes, a lot of the equipment is old, but it works great.

By the way – you CAN connect the T1 WICs back to back using a T1 crossover cable. Many other types of cards (ADSL cards for instance) don’t allow you to do this.

A T1 crossover cable (Integrated or external CSU/DSU is required)

When away from the house, I quickly become fond of  Dynamips (a Cisco Router emulator based off of QEMU). Only after the exam did I learn the beauty of GNS3, a great front-end for Dynamips that allows one to lay out a network graphically. (Which saves a lot of time as I was previously building everything by hand).

GNS3 - making network simulation easy

When using GNS3, I personally recommend also using PuttyCM to enjoy the use of tabbed Putty connections to your simulated equipment. I believe a youtube video from Train Signal is what ledme to PuttyCM (although it appears they may have been using something slightly different):

This is PuttyCM

As I mentioned, the course provided a few decent pieces of software – the first being Network Visualizer. The biggest pro to Network Visualizer is that it doesn’t require a copy of an IOS image to run a simulated router. It does cause CPU to ramp at times (of course Dynamips does the same thing emulating a device), and it is limited in IOS commands, but for an introductory piece of software, it’s not bad.

This is RouterSim

The real beauty in the RouterSim Suite is CertSim. CertSim is almost the exact same experience one has at taking the actual exam. I’m not sure how many questions are in the CertSim question bank, I only ever came across a very very small number of Simlets though. I should disclose that I actually worked with CertSim for about a day, as I’d not realized I had it:

A realistic simulation of what the CCNA exam is like.

Having plenty of PTO to burn, in the end I decided to schedule my exam on a Monday, and take off the previous Friday. 3 days of nothing but studying (well, I took  breaks here and there to play with my latest toy and grab more coffee) and Monday I got the cert.

Next up? The first of 3 exams for the CCNP.

Password Manager

I’m still amazed at the frequency in which I see someone in the IT field open up a M$ Word document or spreadsheet with all their passwords in it. What’s even more baffling is often times they’ll store this password file on a shared drive – shared with all members of the company or group.

For years, I used PWManager to store the hundred or so passwords I needed access to. Like most password managers, you have a database file with a master password.  The master password pretty much unlocks everything.

This was PWManager

I really liked PWManager. There were obvious things missing – most importantly a command line or NCurses based way to access your password database. Overall though – I always found it to be solid.

Unfortunately upgrades to my workstation in the last 12 months have rendered it practically useless. (Gentoo went to KDE4, unfortunately PWManager was written for the KDE3 libraries)

I’d searched for a while, evaluating a few open-source password managers before finally settling on KeePassX.

This is KeePassX

KeePassX is based on the QT4 library, has decent search features, and really expands upon what PWManager provided.  When I initially migrated to KeePassX, the one thing that bothered me was the missing “systray-like” ability to right-click on the minimalized application icon, manuever quickly to a group, then username – and copy the selected password into the clipboard.

<Dog learning new trick>In the end, the KeePassX search bar really does provide a quick way to accomplish the exact same thing.</Dog learning new trick>

When you’ve highlighted an entry (after searching for it),  CTRL-B copies the username to the clipboard, CTRL-C copies the password to the clipboard. You can also set expiration dates for passwords, associate URLs and comments to each entry, and select unique icons for various passwords.

Another benefit to KeePassX is its ability to import database files from other password managers. It should be able to import KWallet and PWManager files, although I found that import process didn’t work properly (“Compressed files are not yet supported” when trying to import from PWManager) . Thankfully a former co-worker already scripted the conversion of an exported PWManager CSV password file to a KeePassX XML file, which can then be imported with very little issue.

KeePassX also runs on OSX, Windows, and Linux. (I used to have issues occasionally where I’d have to reboot my dual-boot machine to grab a simple password from PWManager – but not anymore). The cross-platform support also means that I can now share a password database with my girlfriend (which makes paying online bills much easier)

I’d seriously recommend KeePassX to anyone saving their passwords in an easy to read text-file. It’s easy to use, pretty, and it gets the job done. Of course, I’m all ears if someone has a better password management system they’d like to recommend.

Internet Explorer Error -1072896658

I’ve been having an issue today with a cryptic (which seems to be the norm for Microsoft) error message. Well, actually it was just an error number:


I was in the midst of adding some minor AJAXified code to a corporate website. The test site works perfectly, however whenever accessing the javascript Object/member xmlHttp.responseText on the release site, I get that magical number of death.

Thankfully Pavan Keely had already done the research on this one – IE is wigging out due to Charset issues. Sure enough, the apache directive “AddDefaultCharset” was set to none. Fixing that, fixed this annoyance.