Articles by Scott Hebert

1. WordPress Permalinks Not Working

   Posted on July 30, 2010 in System Administration

   While setting up a new blog for an old site the other day, I ran into a situation where the main page would work, but individual posts would result in a 404 (page not found) error. Checking the error log revealed that Apache could not find the file it was …

2. Show Cisco Interface Status and Traffic Rates Only

   Posted on July 24, 2010 in Networking

   I would hope there is a better way to do this. The other day, I had a need to see all the interfaces on a router and how much input and output traffic they were passing. This just seems like something that should be built in, but I've not seen …

3. Configuring Syslog for Your Cisco Routers and Switches

   Posted on July 23, 2010 in System Administration

   Configuring your syslog server to accept logging output from your Cisco routers and switches requires a few basic steps. We'll assume that you are using a new server and haven't made any previous changes to the syslog configuration. I use <acronym title="Red Hat Enterprise Linux">RHEL</acronym> 5 most …

4. tshark Fails: Interface is Not Up

   Posted on July 20, 2010 in System Administration

   This problem happened on a Mac Mini running OS X 10.4 (Tiger) not too long ago. The user was trying to run tshark against interface en2 — a USB <acronym title="Network Interface Card">NIC</acronym>. The tshark command produced the following output.

   # tshark -w /tmp/slap -i en2
   Capturing …

5. Cisco Input and Output Queue Drops

   Posted on July 19, 2010 in Networking

   This seems to be a pretty common problem for Cisco users. Not that Cisco devices have more queue drop problems, just that more Cisco users are a little confused by the information generated in the show interface command.

   Specifically, we're talking about the lines that look something like this:

   Input …

6. Reminder: Reinstall XQuartz After Apple Software Update

   Posted on July 18, 2010 in Software

   I always forget to do this. Long ago I installed XQuartz on my Mac OS X 10.5 (Leopard) desktop. For the life of me, I can't remember why I installed it. XQuartz replaces the X11 that comes with Mac OS X. I might have done this since XQuartz is …

7. Two Random Asterisk-Related SQL Queries

   Posted on July 15, 2010 in voice

   I hate losing useful SQL queries, so I tend to save them. Ever so often, I stumble across a file of queries from some work I was doing months ago. The following two queries are just such a case. I was analyzing some call data for a call center that …

8. Minicom: device /dev/ttyS0 is locked

   Posted on July 12, 2010 in System Administration

   It seems like I have been working with Mac OS X serial ports a lot lately. Since the Mac in question is hundreds of miles away, I've been doing all of this via the command line using tools like kermit and minicom. One error that we ran into recently was …

9. Is Microsoft Security Essentials for Business?

   Posted on July 09, 2010 in IT Management

   Considering the economy and the crunch that many IT departments are feeling, it is no surprise that many small to medium businesses are curious about using Microsoft's free security product as a replacement to the enterprise security solutions they have been using. Individual businesses will have to decide if Microsoft …

10. Cisco 7200 with Corrupted IOS Image or Faulty ATA PCMCIA Flash

    Posted on July 08, 2010 in Networking

    If you find yourself in the situation where a Cisco 7200 series router has a corrupted IOS image or the flash drive has gone on the blink, the following documents may be useful to you. Not all of these documents are Cisco 7200 specific, but they are all useful.

    • Standard …

11. install_driver(Sybase) failed: Can't load 'Sybase.so' for module DBD::Sybase

    Posted on July 01, 2010 in System Administration

    install_driver(Sybase) failed: Can't load '/usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi/auto/DBD/Sybase/Sybase.so' for module DBD::Sybase: libct.so.3: cannot open shared object file: No such file or directory at /usr/lib/perl5/5.8.0/i386-linux-thread-multi/DynaLoader.pm line 229.
     at (eval …

12. Cisco iperf Equivalent or Cisco-based Bandwidth Testing

    Posted on June 30, 2010 in Networking

    If you've worked on networks long enough, you're probably familiar with iperf. This application is great for testing throughput between two computers on your network. Unfortunately, if you find yourself in a situation where you have less than two computers to test with, iperf is less than ideal.

    Fortunately, Cisco …

13. Subversion: Revert to Earlier Version

    Posted on June 29, 2010 in Programming

    This is one of those annoying little things I have to do ever so often. There are two different commands to accomplish this task depending on the specific situation.

    If you've made a lot of changes to a file and need to back all of those changes out, you can …

14. Domain Prices Going Up Again

    Posted on June 16, 2010 in IT Management

    I got a call from GoDaddy the other day warning me that VeriSign is raising the price of domain registrations. This seems like a big deal because the price hike is happening on July 1st. The truth, though, is that VeriSign announced the price increase six months ago in December …

15. Rate-limiting SSH connections with iptables

    Posted on June 14, 2010 in System Administration

    If you have SSH open toward the Internet, you are surely aware of the number of brute force password attempts your server sees everyday. Although a good password policy may make these attempts nothing more than an annoyance, each connection to your SSH daemon takes up valuable server resources. I …