Todd's TechnoGeek Journal

Steer Clear of ClearWire

Todd A. Jacobs — 2006-06-22T13:08:17-08:00

I know I usually rip on Charter when I post about rotten ISPs, but I thought I'd give things a change of pace by ripping on ClearWire for a while instead.

After my latest round of problems at Charter, I thought I'd give ClearWire a try. It turns out that they're even worse; they won't tell you which ports they block, but my experience is that they are at least blocking all service ports below 1025. When I spoke to customer disservice about it, it turns out that they do this even with their "business" class of service. In other words, your idea of business use of the Internet must be pretty much confined to surfing the web in order for you to find ClearWire useful--and I use the word "useful" advisedly.

I have to admit that their Orwellian insistence on saying "Yes, we manage those ports for our customers" every time I used the word "blocked" was an interesting use of new-speak, but not interesting enough to use them as an ISP. I suppose they think that if they say "managed" instead of "blocked" often enough, people will start to think of it as a value-added service instead of a bowdlerization of the Internet.

Anyway, I wanted to save some of my fellow geeks the trouble I went through. YMMV...but in this case, I rather doubt it.

Say HELO to Less Spam

Todd A. Jacobs — 2006-06-22T12:53:31-08:00

I haven't updated this blog in a while, but it's not because there aren't geektastic things going on in my life. There are only so many hours in the day, after all, and sometimes blogging is the first thing that has to go when things get hectic.

I've recently beefed up the anti-spam tactics of my codegnome.org domain. As I may or may not have mentioned before, I take a pretty strong defense-in-depth strategy to spam. My toolbox includes various blocking techniques at the SMTP server level, as well as revocable email addresses, a challenge-response system, and Bayesian filters at the individual account level.

I was recently noticing that my mail server was still accepting way too much obvious spam, so I took a look at my Postfix configuration. The first thing I noticed was that I hadn't updated any of my blacklists in a while, so I added the Exploits Block List to my existing Spamhaus SBL queries to get better coverage.

smtpd_client_restrictions =
        reject_rbl_client relays.ordb.org
        reject_rbl_client sbl-xbl.spamhaus.org

I also noticed that a lot of spam comes from non-existent hosts, or hosts that provide incorrect HELO/EHLO messages when connecting. I tightened that up, too.

smtpd_helo_required = yes
smtpd_helo_restrictions =
        reject_invalid_hostname
        reject_non_fqdn_hostname
        reject_unknown_hostname

So far, I've had only one legitimate mail source caught up by the new HELO restrictions, but Postfix allows me to make exceptions in such cases by using a check_helo_access hash table lookup as the first item inside the smtpd_helo_restrictions context.

It's a little hard to quantify, but my off-the-cuff estimate is that the HELO restrictions have reduced the amount of spam allowed in the front door by almost 80% all by themselves. Blocking spam sources before accepting the message for further processing is not only more resource-efficient for the server itself, but it also uses less network bandwidth, which is a good thing for smaller pipes like mine, leaving more of the network available for the fun stuff.

Essential Windows Tools

Todd A. Jacobs — 2006-03-13T16:44:56-08:00

I admit it: I'm a Linux guy. I hate running Windows, as I find the environment restrictive, overly commercialized, and creatively limiting. However, there are times when one simply has to run it. Luckily, there are some great GPL'd utilities that make using it bearable:

Cygwin: a POSIX compatibility suite that provides a Linux-like environment under Windows
GNU Privacy Guard: Public key encryption tools
Windows Privacy Tray: a GUI front-end for GNU Privacy Guard
ClamWin Anti-Virus: An open-source virus scanner
TortoiseSVN: Integrates Subversion revision control into the Windows Explorer
SVNService: runs the Subversion server as a Windows system service
PuTTY: A suite of SSH client utilities, including a GUI

If I'm ever saddled with a Windows system, I try to ensure I have these critical applications installed at the earliest opportunity. If you can't run a real open-source OS, these tools are the next best thing.

Knoppix Reloaded

Todd A. Jacobs — 2006-03-05T22:19:36-08:00

I'm once again trying to travel lighter by leaving my personal laptop at home while flying. In order to accomplish this, I am trying to customize the latest Knoppix release (version 4.0.2) for use with my company-issued laptop. I couldn't find my old Knoppix customizations; those pesky USB thumb drives have a tendency to get lost over time. As a result, I'm having to re-solve some old problems with only vague memories of my previous solutions to guide me.

For example, Knoppix doesn't have a screensaver enabled by default, and it's pretty non-obvious how to get one working. While there are other solutions, here's my current one.

Set a password for the knoppix account.
Copy vlock from an existing Debian box, or build it from source.

Create ~knoppix/bin/vlock.sh as a wrapper for vlock itself:

#!/bin/bash
sudo passwd -u knoppix >&-
sudo openvt -ws -- \
     sudo   -u knoppix bash -c \
            '/home/knoppix/bin/vlock -a \
	     /usr/bin/clear'
sudo passwd -l knoppix >&-

Add an alias to ~knoppix/.bashrc such as:
alias lock='~/bin/vlock.sh'
to avoid confusion.
Run lock in any terminal, and enjoy the screen-locking goodness that follows.

Other nifty tips and tricks are sure to follow.

Doctor Who Comes to SciFi Channel

Todd A. Jacobs — 2006-02-25T12:21:12-08:00

The SciFi Channel begins broadcasting the first season of the new Doctor Who series on Friday, March 17 with a two-hour, back-to-back broadcast of the first two episodes: "Rose" and "The End of the World." I think this is a very smart programming decision, for a couple of reasons.

Firstly, while I liked "Rose," it doesn't really do enough to introduce all the major characters and plot devices on its own. It's only when paired with the second episode that the scope and characterization, as well as the nature of the Doctor Who universe, really begin to come together for the non-Whovian.

I plan to record the entire run on my ReplayTV 5500 so that I can watch them over and over--and perhaps even do a little cavorting to the theme music.

Now that brings back memories better left repressed. :)

Looting at Gallifrey 2006

Todd A. Jacobs — 2006-02-25T12:05:31-08:00

Glindy and went to Gallifrey 2006 last weekend. We had a good time overall. I saw a number of celebrity panels, including a stand-out interview with Louise Jameson, who also did a very funny monologue at the end, and some witty on-stage repartee from Noel Clarke, who plays Mickey in the latest Dr. Who television revival.

A real highlight for me was when Mary Tamm and Pamela Salem came up to say hello to Glindy. They thought she was outstandingly cute, and both seemed quite happy to feed her a small bit of buffalo jerky.

I didn't really make any new friends, or get to get as much socializing or celebrity glad-handing as I had expected, but I did manage to come home with some very cool loot:

a 17-foot Tom Baker-style scarf,
a complete set of the BBV audio and video adventures,
a complete set of Bernice Summerfield audios from Big Finish,
some hard-to-find MP3-CDs from the William Hartnell and Patrick Troughton eras, and
five shirts in various styles, with several different Doctor Who logos embroidered on the pockets.

All told, it was a great time, and I'd definitely do it again in some future year.

Gallifrey 2006

Todd A. Jacobs — 2006-02-11T16:41:52-08:00

Glindy and I are headed to Gallifrey 2006 in Los Angeles this weekend for the 17th annual Doctor Who convention. I've always wanted to go to one of these, but never made the time until now.

Part of the draw, of course, is that Doctor Who is once again in production over at the BBC. Without new shows, I'm not sure I would be as excited about going as I currently am.

While I'm a Doctor Who fan from way back, I've never been a typical fanboy. I'm not excited about dressing up as the Doctor (although I've always wanted a Baker-era scarf), or wandering around convention floors discussing the finer points of TARDIS console design. I do, however, have embarrassing memories of cavorting in front of the TV, doing the happy dance to the show's theme music. I also remember being very depressed when our stone-age VCR from the early 80s--which had manual channel tuners, if you can believe it--slipped out of alignment and cost me a clean recording.

The 2005 season of Doctor Who was fabulous. The production values were high, the characters were great, and the writing was very emotional. The science sucked, of course. As a SF&F geek, I find it hard to forgive the occasional--but inexcusably bad--science faux pas in this show; anyone else remember "The End of the World," where Rose was decidedly not burned by super-heated air as the sun's radiation poured in?

Still, warts and all, I love the updated take on the Time Lord mythos. Christopher Eccleston and David Tenant are both enjoyable as the Doctor, and Rose is destined to be one of my favorite companions of all time, right alongside Leela and Romana #2.

Meanwhile, I'm off to see Mary Tamm (Romana #1) and Louise Jameson (Leela) at the convention. And who knows...I might even find a Baker-era scarf to bring home in my loot bag!

A Society of Mediocrity

Todd A. Jacobs — 2006-01-15T14:57:53-08:00

We live in a society that aspires to the mediocre. Even with our culture's weird fetish for hero-worship and celebrity, part of that twisted idolatry is the idea that celebrities are at their best when they are just like everyone else.

This idea isn't a new one, but it hit home for me again today while watching Smallville. This isn't a new phenomenon; shows like Bewitched, Charmed, and I Dream of Jeannie have been promoting the same hidden agenda for decades.

Consider the unsubtle message of these shows. Most of the shows revolve around people jumping through self-imposed hoops to be "normal." Take careful note that this isn't the same as trying to be accepted, or liked, or to fit in at school or the office. No, these are characters who are filled with self-despite because they aren't "just like everyone else."

Oh, occasionally the drama touches on their feelings of loneliness, of feeling like outsiders, but this is quite secondary. If you watch carefully, what they really dislike is being different. They haven't been ostracized because others see them as different; no, they themselves simply feel unworthy because they aren't squarely in the middle of the mainstream. They treat "being normal" as a synonym for "being happy," and yet never achieve either state--nor any awareness that they have wrongly conjoined the two in their own minds.

As a lifelong outsider myself, I find this attitude hard to comprehend. Being "just like everyone else" doesn't necessarily make you liked, or accepted as one of the group. No, it just makes you less than you are, and less than you could be. Why would anyone aspire to that?

Yes, I realize these are only TV shows. But I think they speak to the zeitgeist of our times, or their messages wouldn't be so easily accepted. To pass without comment, such ideas have to be considered common sense, and presumably self-evident to anyone who is "normal."

Being accepted is great, and being liked is terrific--but do we as a people truly feel that the only way to be liked or accepted is to be without any special merit? That being talented, smart, or strong are things to be hidden? That special skills should be buried deep, or renounced altogether? The very idea saddens me.

My skills and abilities are neither superhuman nor magical, but they do make me different. Sometimes I wish it were easier to find acceptance, and to be liked, but I've never made the mistake of thinking that being less than I am was the missing ingredient for a life of happiness.

If these shows really are an artistic mirror held up to life, it's an ugly picture indeed. Can you honestly say you want that image as your self-portrait?

Thank Goodness for Google

Todd A. Jacobs — 2006-01-08T14:37:43-08:00

Google revolutionized the search industry in a lot of ways. One of the most useful--but often overlooked--features is the Google cache. As Google spiders the web, it often takes "snapshots" of web pages at various points in time. I have no idea how long it keeps cached pages, but the fact that it does so can be amazingly useful.

As I may have mentioned before, my old web server blew up a few months back. All data was lost, and *of course* I had no current backups. One of the many things that went kablooie was my old blog.

I thought many of those pages gone forever, and decided to start over. Well, while I was idly Googling myself today, I ran across some of my old blog entries in the Google cache. Yay!

So I grabbed as many of the cache files as I could find, and am slowly reimporting the entries, with the original dates (but not time stamps) intact. The loss of time stamps is due to the fact that Blosxom used the blog entry's mtime for the time stamp, whereas Nanoblogger uses a combination of filename and per-entry keyword.

Either way, the end result is that most of the material from my old blog is being resurrected; just scan back through the 2004 and 2005 archives to find it. I hope you find it useful.

Yahoo Groups: Undocumented Commands

Todd A. Jacobs — 2006-01-06T14:40:36-08:00

Administering your options on Yahoo Groups mailing lists can be a little annoying, because Yahoo really wants you to use their web interface for configuration rather than sending control emails to their mailing list software. It makes economic sense to them, because they get ad revenue for every eyeball that hits their web site, but nada for running the lists themselves.

Personally, I don't *want* to log into Yahoo to deal with my list options. Not only is it inconvenient, but it ties my subscribable addresses to those on my Yahoo account, which doesn't always work well if you use revocable email addresses (see TMDA) for spam filtering, like I do.

However, underneath the hood, it appears that Yahoo Groups makes use of qmail+ezmlm, so most configuration options can be managed by addressing emails to certain list extensions--provided you know what they are. So, given the mailing list foo@yahoogroups.com, the following address extensions should always be valid:

To join/leave a list:

Subscribe

foo-subscribe@yahoogroups.com

Unsubscribe

foo-unsubscribe@yahoogroups.com

To change mail options *after* you've subscribed:

Enable Digest Delivery

foo-digest@yahoogroups.com

Enable Non-Digest (Per-Email) Delivery

foo-normal@yahoogroups.com

Hold Delivery (but remain subscribed)

foo-nomail@yahoogroups.com

It is worth noting that, as far as I can tell, you can't subscribe directly to the digest version of any list on Yahoo Groups. You have to subscribe first, and *then* enable digest delivery. Strange but true.

I hope knowing this helps others as much as it does me, and I hope that savvy list owners make this information more readily available in future.