Articles by Scott Hebert

  1. Server Naming Conventions

    Posted on in System Administration

    Every machine needs a name. As soon as the second server is ready to go, the name SERVER no longer seems like a great idea. When deciding how to name servers, there are two primary conventions: functional names and unique names.

    Functional Names

    Functional names take the job assigned to …

  2. UDLD In Radio-Based Metro Ethernet Rings

    Posted on in Networking

    <acronym title="UniDirectional Link Detection">UDLD</acronym> is a Cisco protocol designed to detect and disable unidirectional links in Ethernet (fiber or twisted-pair). In the case of a radio-based Metro Ethernet ring, UDLD goes the extra mile in preventing Spanning-Tree loops and user service interruption.

    4 Switches and Spanning-TreeIn this simple network of …

  3. VoIP Hairpinning Issues

    Posted on in voice

    When using Asterisk and a remote bank of <acronym title="Primary Rate Interface">PRI</acronym>s (or any other form of <acronym title="Public Switched Telephone Network">PSTN</acronym> connectivity for that matter), you may encounter an issue known as hairpinning. Hairpinning describes what happens when a call coming from …

  4. Courier authdaemond Breaks On Hidden Whitespace

    Posted on in System Administration

    A buddy of mine was recently setting up a new installation of Courier with virtual user support via MySQL. He ran into an issue when trying to get authdaemond to connect to a remote MySQL installation. No matter what he changed in authmysqlrc, the following kept appearing in his mail …

  5. Command Logging is Vital to System Administration

    Posted on in System Administration

    If you're like me, it probably seems obvious that command logging is an important part of system administration. Any change I make, whether it's on a router or server, is logged somewhere. Although folks give plenty of reasons why they don't use tools like sudo for super-user functions (inconvenience and …

  6. Adding Mac OS X Users Remotely

    Posted on in System Administration

    Important commands: ditto nicl nidump passwd

    If you're like me, you might be occasionally called upon to remotely manage a few Mac OS X systems. The environment I'm working in only allows SSH access to these systems, so everything must be done from the command line.

    Unlike Linux and most …

  7. Implement a Sensible Naming Policy in Cisco IOS

    Posted on in Networking

    It used to be that access lists in Cisco IOS were numbered. Not only were they numbered, but the numbers were significant to what kind of access list they were. Now access lists (and just about everything else) can be named rather than numbered. Although this seemingly innocuous change has …

  8. Initial Thoughts on ScribeFire

    Posted on in Software

    I recently started using ScribeFire as my blogging client. Here are some initial thoughts on it.

    • ScribeFire is not an offline editor. As far as I can tell, there is no way to store unpublished content locally. In terms of usefulness, this probably goes both ways. It's a pain when …

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