Toil: Ethernet, Comment Previews, Trackbacks, and WordPress Updates

I love working with computers, but sometimes it can be a chore. You want to work on one thing, but other things break and you have to deal with them sooner or later. It can feel like such a burden. Petty distractions from what we really want to do. Do you ever get the feeling we’re building a big technological house of cards?

But it’s always satisfying to fix things and keep the night at bay for a little while longer.

Ethernet

My wife mentioned Friday she couldn’t get to her GMail account, which I mentally filed as a possible transient connection problem. I’ve had a couple of network hiccups lately where I needed to reset my router and a switch. She wasn’t trying when she told me, or trust me I would have immediately dropped everything to address important customer concerns. Things were working on my machine, so I didn’t think much of it. Later I went on that machine to check movie listings and saw that it was out of the loop.

Sparing you the whole tedious troubleshooting story, I determined it was probably a hardware port problem. (I tried a new cable, tried changing ports on the router to one I knew was working, tried booting with a Live CD, tried using a static IP, etc.) I felt some aggravation. This is the new system 76 machine I bought last November. It was either a hardware failure on a ten-month-old machine, or some obscure software problem that appeared out of the blue. (Overall, the machine has been great, and we’ll see what their support has to say.)

I decided to try plugging a spare Ethernet card into the machine, with more than a little trepidation at possible configuration difficulties. Well, I’m happy to report it was simple. GNOME‘s network config tool (System » Administration » Network) made it a no-brainer. The new card was detected; I just had to enable it and then DHCP took care of the rest. I wasn’t all that surprised, given my experience so far in Ubuntu and GNOME, but I guess I have a healthy sense of pessimism. (Let’s call it healthy.)

And this is as it should be. Ethernet should be simple and well-supported by now.

Problem #1 fixed. (Not solved. I don’t have a definitive answer on what was wrong with the original Ethernet port, but spending an hour trying a new card is much preferred to a whole day troubleshooting.)

WordPress Comment Previews

Since setting up my local development WordPress blog in its current home, Zodiac, I’ve had a problem with individual post pages. The HTML would be cut off at the point where the comment section should appear. I didn’t have this problem on Prometheus where I first installed it. I figured out that it was related to my comments preview plugin, but couldn’t figure out why I was now having this problem. It bothered me and made it harder to validate new blog posts, but I let it go for a while.

Maybe inspired by my success in dealing with the Ethernet problem, I took another stab at this. I looked at the Filosofo Comments Preview plugin page. One of the posts in the help forum described a problem similar to mine, and I realized there have been newer versions of the plugin released. Well, duh, let’s see if that helps. And it did. Why didn’t I think of upgrading sooner?

The new 1.0.1 version is much improved and streamlined over the 0.7.8 version I had been using. The preview appears at the bottom of the comment list on the post page now, making a separate preview page (where it’s harder to peek back at what you’re commenting about) unnecessary, and eliminating redundant template pages. There used to be a lot of options and captcha stuff, but this is all gone now, which is fine with me.

Thanks, Il Filosofo. Great work.

Problem #2 fixed.

WordPress Trackbacks

Amy Stephen over at the prestigious (Free and) Open Source Community site is kind enough to link to some of my posts here, and she noticed that trackbacks stopped working about a month ago. I really wanted to fix this and be a good blog community member, but was defeated in my initial troubleshooting attempts. So it went on the shelf for a while. It’s one of those things that I think is important to have working correctly; I take some pride in running this web site and don’t want to be guilty of shoddy workmanship. But on the other hand, movintofreedom.org is kind of an obscure site and doesn’t attract a lot of links. How much time should I invest?

Perhaps further emboldened by having fixed two problems yesterday, I pressed on to look at this one. First, I was hopeful that it could have been a problem with the comments preview plugin, and that the newer version would see things working again. But no.

Back to Google. I found a couple of threads where people mentioned looking at the Apache logs. I had done this previously but went in for another look. I found that my trackback attempt from wordpress.com had gotten an HTTP response 406 “Not Acceptable.” Keying in on that, I searched [wordpress trackbacks 406] and found:

http://wordpress.org/support/topic/94402, which led to http://wordpress.org/support/topic/110898 and the suggestion that the problem was with Apache’s mod_security. This can be disabled by adding to the .htaccess file:

<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

And that did the trick! What a relief. Now, is this a smart thing to do, disabling mod_security? I previously ran in to problems with this module when it prevented me from posting an entry on my blog that contained the word “Perl.” So I was aware that it could be an annoyance. But I imagined it might be doing some good also.

I followed up with my host, SurpassHosting. I opened up a ticket about this a while back before I knew about the mod_security angle, and they suggested I contact WordPress support first. (At which point I had given up for a while.) Anyway, I followed up on my original ticket and mentioned that disabling mod_security solved the problem, so my guess was that they had configured it to be more aggressive sometime after May 20 which caused pingbacks and trackbacks to break. I asked them what they thought, and wondered if turning it off for my site could be a problem for the whole shared server I’m on. An admin got back to me with:

Mod_Security is an intrusion detection and prevention engine for web applications. Operating as an Apache Web server module, the purpose of Mod_Security is to increase web application security, protecting web applications from attacks.

By adding the entry ” SecFilterEngine Off ” in .htaccess file, all mod_security rules will be disable for your domain. We wouldn’t recommend this because it will help the attackers to exploit the vulnerabilities in any web application you used.

From the log we could find that the post header rules blocking your application. try to disable only the post rules by adding ” SecFilterScanPOST Off ” & ” SecFilterInheritance Off ” in htaccess file. Add the entry ” SecFilterEngine Off ” only if it is absolutely necessary.

So:

<IfModule mod_security.c>
SecFilterScanPOST Off
SecFilterInheritance Off
</IfModule>

And that worked for my trackback test and for 50% of my pingback tests. That’s 1 out of 2 ping tests. I don’t know what happened to the first one — maybe Akismet swallowed it up. Day to day I don’t see a lot of (or any?) pingback or trackback spam in my Akismet holding pen, so I wonder if it gets removed before we even get to see it.

(Let me put in a final good word for SurpassHosting. I’m really happy with their service. I thought the request to try WordPress first was reasonable and I didn’t feel put off by it. I gave up at the time because I didn’t feel like digging just then. Surpass has been very responsive and helpful whenever I’ve contacted them. Which hasn’t been all that often; they’re pretty good.)

Problem #3 (hopefully) fixed.

WordPress 2.0.11 Update

I woke up today, still pleased with all of my handiwork from yesterday, still relieved to have the burden of tasks undone lifted, only to find that version 2.0.11 of WordPress was released overnight. Man, there is just no rest for the wicked.

But it is a fairly simple upgrade and easy to update the 22 files that had changed from 2.0.10. No ill effects noticed so far. I think it’s awesome that they’re supporting the 2.0.x line until 2010. I have no immediate desire to upgrade and it’s nice that I can count on security fixes for a long time.

WordPress is a super example of free software, I think largely because Matt Mullenweg really gets it. See: Price of Freedom.

Now,

If you notice anything else wrong with the site, please let me know. But not for a week or so, ok?

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