October 2011 Issue of Linux Journal: Networking

SneakerNets and BNC Terminators

I first started my sysadmin career about the time in history when 10BASE2 was beginning to see widespread adoption. ThinNet, as it also was called, meant an affordable transition from the SneakerNet so many businesses used. (SneakerNet is a term for walking floppy disks back and forth between computers—not really a network, but it’s how data was moved.) Anyone who remembers those years knows ThinNet was extremely vulnerable to system-wide failures. A single disconnect (or stolen BNC terminator cap at the end of the chain) meant the entire network was down. That was a small price to pay for such inexpensive and blazing-fast speed. 10Mbit was the max speed ThinNet supported, but who in the world ever would need that much throughput?

Networking has changed a lot since my career started, and it’s issues like this one that keep me up to date. Kyle Rankin starts off with a hacking primer using an off-the-shelf home router (follow this link to read the full article now-- it's open to all as a free preview of this October issue). This isn’t merely the old WRT54G hacks you’re used to reading about. Instead, Kyle shows us how to don our black hats and really hack in to a D-Link wireless 802.11n router. If Kyle’s hacking tutorial makes you a little nervous, don’t worry; we have some network security this month as well. Henry Van Styn teaches us some advanced firewall configurations with ipset. Granted, firewalls won’t protect anyone from PHP vulnerabilities, but they still help me sleep better at night.

Mike Diehl switches gears, and instead of showing how to hack (or protect) the network, he describes how to create. Specifically, he explains how to create network programs that are cross-platform and easy to build with ENet. As someone whose programming skills peaked with 10 GOTO 10, Mike’s idea of “easy” might be relative, but he gives coding examples, so even copy/paste programmers can join in.

Henry Van Styn has another article in this issue on how to use tcpdump to troubleshoot network issues effectively. If you’re in charge of a large network, you owe it to yourself to polish your tcpdump skills. It’s a tool every network administrator needs, and Henry takes some of the mystery out of it. Adrian Hannah follows in a one-two punch teaching us how to sniff packets effectively. Packet sniffing is one of those skills that can be used for good and evil both, but we’ll assume you’ll use your powers for good. At the very least, you’ll understand what sort of information is available on your network so you can try to secure it a bit.

Networking also has made so many other facets of computing possible. If it weren’t for networking, we wouldn’t have cloud computing. Adrian Klaver shows how to use Python to work with Amazon Web Services. For some of you, cloud computing is scary, because you never get to access the computer you’re working on directly. One way to help alleviate the concern of working on computers far away is to implement remote viewing. Joey Bernard covers several methods for accessing a computer remotely, whether it’s in the next room or on the next continent. Granted, that doesn’t work for cloud-based services, but it does for remotely hosted servers, so it’s an article you’ll want to check out.

Our networks are even home to filesystems nowadays, and Petros Koutoupis shows how to deploy the Lustre distributed filesystem. Utilizing multiple nodes for file storage is a great way to leverage your network resources for speed and redundancy. Regardless of your network speed, however, data will travel only as quickly as the hard drive underneath will send it. Kyle Rankin reviews the Intel 320 series SSD this month. If you haven’t taken the plunge to SSD, after reading about his results, you might decide that now is the time.

And, of course, for those of you who think networking is good only for accessing your e-mail, we have articles for you this month too. Programmers will like Reuven M. Lerner’s article about his mustache—more specifically, Mustache.js, a JavaScript templating system that might be right up your alley. Dave Taylor shows us scripters how to manipulate image files without ever leaving the command line. There’s nothing wrong with firing up The GIMP to edit a graphic file, but sometimes you just want to scale an image quickly. Dave explains how.

We’ve also got new product debuts, Linux news and interesting things I’ve stumbled across this month in the UpFront section. So whether you’re carrying this issue around on a Flash drive (SneakerNet anyone?) or downloading it wirelessly from the wireless router you just hacked, we hope you enjoy it. We certainly enjoyed making it.

Linux Journal October 2011 Issue #210

Editorial Focus: Networking

Available to Subscribers: October 1




Shawn is Associate Editor here at Linux Journal, and has been around Linux since the beginning. He has a passion for open source, and he loves to teach. He also drinks too much coffee, which often shows in his writing.


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This Issue Knowledge me

Koswandy's picture

Hello, thanks you for share this information, I will waering it for referention my study IF Ultrabook Notebook Tipis Harga Murah Terbaik

Kindle Edition

tom45555's picture

Just wanted to say Thanks for the Kindle .mobi format. Works great, I can hardly wait to try this out on the new Kindle Fire.


Kindle Edition

Linux_Kelley's picture

When you went to the Digital Edition only last month I asked that you also come out with a Kindle Edition.
Thank you for doing so.
I have the large screen Kindle DX and the Kindle Edition is great!


Carlie Fairchild's picture

We're still tweaking both the EPUB and Kindle editions regularly but I'm with you, the Kindle edition is great. I'm personally loving it too.

Thanks for telling us you wanted a Kindle edition. It was you and other readers who voiced their opinion that kicked us in to high gear to get it done.

Thanks again

Carlie Fairchild is the publisher of Linux Journal.

Another feature gone?

carlfink's picture

What, no podcast?


Carlie Fairchild's picture

Hi Carl,

You are correct that the podcast as we once knew it is no longer. However we're spending those time resources on producing video content for the digital edition (you can check one of them out in our October issue of LJ). The podcast wasn't getting a lot of traction, unfortunately -- even though there were a few of us who loved it (me!).

Carlie Fairchild is the publisher of Linux Journal.

Wow... very sad.

garrett's picture

I'm sad to hear that. I've got every issue of Linux Journal, and always enjoyed reading it. I suppose they'll be refunding unsent issues, but I haven't heard from them yet...

Link no worky

Kernwig's picture

The link to the preview article just gives a blank page. I guess it doesn't work in Linux. :-/

(Garrett, Linux Journal is an e-magazine now. No more paper.)


Carlie Fairchild's picture

We can't seem to recreate the problem you're having on this end (and there's a lot of Linux being used here so it's not specifically that). But shoot, I want you to be able to see the article and certainly don't want others to run in to this. If you wouldn't mind, would you ping me at carlie at linuxjournal dot com and let me know which distro you're using as well as which browser and browser version? I hate to ask you to do that, but would love to debug this.

Carlie Fairchild is the publisher of Linux Journal.


garrett's picture

Are new issues not being mailed? I'm seeing tons of Facebook activity, but no Linux Journals in my mailbox...


Carlie Fairchild's picture

Hi Garret,

Kernwig is correct. As a subscriber you should have received (multiple) notifications about the transition so I'm very sorry to hear you that for some reason you didn't! Will you mind pinging me at carlie at linuxjournal dot com with your contact info? We'll get your subscription info looked up and get back to you with more data ASAP.

Carlie Fairchild is the publisher of Linux Journal.