Articles by Scott Hebert

1. New-Style TACACS+ Configuration

   Posted on June 06, 2011 in networking

   For troubleshooting tips regarding the error message %TAC+: no address for get_server see: Troubleshooting "%TAC+: no address for get_server" on Cisco Devices.

   While working with Cisco Catalyst IOS image 12.2(58)SE1, I noticed that configuration for TACACS+ had changed. My first clue that there was a problem was …

2. Limiting SSH Connections with ufw

   Posted on May 30, 2011 in System Administration

   In the past, I've written about the usefulness of using iptables to limit incoming SSH connections. Although it isn't a replacement for a good password policy, it at least limits the ability of outsiders to perform a brute-force password attack on your system. Now that I've started using Ubuntu more …

3. rsync: on remote machine: --extended-attributes: unknown option

   Posted on May 27, 2011 in System Administration

   rsync: on remote machine: --extended-attributes: unknown option
   

   If this is the output you get when running rsync, you are almost certainly running the Mac OS X version of rsync -E on the client with something else on the server side. The fix is to install the MacPorts version of rsync …

4. ab Results Before and After Server Move

   Posted on May 25, 2011 in System Administration

   

   Behold, the benefits of virtualization!

   I spent most of the evening preparing to move a few websites. I decided to do some benchmarking just to see what sort of improvement I was getting from the new server setup. Although the old server didn't feel slow when browsing sites, the results …

5. Ubuntu: Installing VMware Tools in 10.04 LTS

   Posted on May 23, 2011 in System Administration

   Although this process is well documented on the Ubuntu community site, I decided to take notes of the exact steps that I took so that I wouldn't have to fumble through that long document next time. I'm installing the tools in a clean install of Ubuntu 10.04.2 LTS …

6. WordPress: Tired of Dashes and Quotes Being Rewritten?

   Posted on May 21, 2011 in Software

   Using WordPress to write a technical blog can be occasionally frustrating. WordPress uses the wptexturize() function to rewrite certain ASCII character combinations into HTML entities. Although this may generally be a "good thing," it's really annoying on technical blogs where two dashes is not an em dash.

   To disable this …

7. MySQL Multiple-Column Indexes: Order Matters

   Posted on May 18, 2011 in Programming

   This will just be a short reminder. If you're planning to create multiple-column indexes in MySQL, remember that the order of the columns matters. As the MySQL documentation points out, any "leftmost prefix of the index can be used." This means that the index can be used for any number …

8. How Big is the World of Cloud Computing?

   Posted on May 02, 2011 in System Administration

   

   Via: Wikibon

9. The Influences Driving Virtualization

   Posted on May 02, 2011 in IT Management

   The Influences Driving Virtualization is a new white paper from the guys at ReadWriteWeb. I recently downloaded and read through it. If you're curious about virtualization, but aren't sure about giving up your contact info to ReadWriteWeb, here are some notes about what you'll find after you download.

   "Organizations that …

10. Are You Getting Started with VMware vCenter Chargeback Pricing Matrices?

    Posted on April 19, 2011 in Software

    In vCenter Chargeback version 1.6, VMware added the ability to define a pricing matrix for virtual machines in a virtual data center (vDC). A pricing matrix associates a fixed cost with the virtual machine based on the number of allocated vCPUs and RAM. If you're implementing a bundle-based pricing …

11. ARIN Comments on IANA Functions

    Posted on March 31, 2011 in IT Management

    The National Telecommunications and Information Administration (NTIA) recently requested comments from concerned Internet entities regarding the Internet Corporation for Assigned Names and Numbers' (ICANN) performance of Internet Assigned Numbers Authority (IANA) Functions. ICANN currently holds a contract with the NTIA to that is set to expire in September of 2011 …

12. Adding Windows Shared Printers to Mac OS X 10.6 (Snow Leopard)

    Posted on March 29, 2011 in System Administration

    I was recently struggling to add a Windows shared printer to my MacBook Pro (running Mac OS X 10.6 (Snow Leopard)) until I ran across this post which gave me two important hints:

    1. You need to use the Advanced tab in the Add Printer dialog. You can find this …

13. Adding Devices to Cacti in Bulk

    Posted on March 25, 2011 in System Administration

    I recently had to add over 100 new devices into Cacti. Believe it or not, you can do this in bulk using the command-line tools provided with Cacti. I used to add_device.php, add_tree.php, and add_graphs.php scripts to get the job done.

    First, I created a file (/tmp …

14. WordPress Stops Redirecting, Reset Permalinks

    Posted on March 09, 2011 in Software

    This is the first time I've run into this problem.

    In the process of disabling some slightly used plugins, slaptijack.com got into a situation where every permalink simply pulled up the home page rather than individual posts. I checked everything (mod_rewrite in my Apache configuration file, changes to .htaccess …

15. If Your Post Doesn't Start With An Image, Display an Ad Instead

    Posted on March 08, 2011 in Programming

    I usually start my posts off with an image that is relevant to the post. I think it adds a bit of drama to what I'm writing about, and it also gives me a nice place to anchor a link to a WordPress tag about the subject. I had this …