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Using IPv6, Security Through Proxy, Open Source Telephony, and Postfix Troubleshooting

by chromatic
Linux Newsletter for 01/26/2004

Hello, readers. Welcome to the Linux newsletter, a weekly review of the new articles and weblogs on Here's what's new this week.

Ibrahim Haddad started the week with Connecting to the IPv6 Internet, a followup to his earlier article about enabling IPv6 support on your Linux box. This week, Ibrahim demonstrates how to connect to the 6bone (and why you'd want to) by tunnelling IPv6 over IPv4. Hopefully, as more ISPs support IPv6, tunneling will be less necessary. For now, it's probably your best option.

If you're looking for something a little more practical, Nitesh Dhanjani has contributed Web App Security Testing with a Custom Proxy Server. That's a mouthful. The idea, however, is very simple. For people to use your web application, they have to download HTML, including forms. At that point, they can do anything they like — changing values, adding parameters, and bypassing any client-side security you thought you might have had. Nitesh demonstrates how to create and run your own proxy, which will allow you to change these parameters at will, to ensure that your software can handle it gracefully.

Is there a place for open source software in the telephony world? It's starting to seem likely. John Todd's VoIP and POTS Integration with Asterisk explains how to configure an Asterisk-based PBX system to accept calls from other systems on the Internet. Can VoIP and Asterisk save you money and add more features? Quite possibly.

Finally, Kyle Dent, author of Postfix: The Definitive Guide, provides Troubleshooting with Postfix Logs. This article gives several troubleshooting tips, including suggested configuration techniques, before explaining how Postfix logs work and how to find the information you need.

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This week's weblogs feature Steve Mallet explaining that Linux's second greatest asset is its people, Bruce Stewart explaining why we disabled anonymous talkbacks, Derrick Story covering IBM's Linux PowerPC Pitch, Adam Trachtenberg recounting adventures at LinuxWorld Expo, Jonathan Gennick resolving to explore Sun's Java Desktop, and Andy Oram musing on trends and conversations from LinuxWorld Expo.

Upcoming article topics include cellular networking, version control systems, advanced Python networking, and clustering. Stay tuned!

That's all for now,

Technical Editor
O'Reilly Network and Linux Devcenter Top Five Articles Last Week

  1. An Introduction to the Twisted Networking Framework
    Network programming is difficult, and not just because bandwidth and latency are hard to manage. Sending and receiving messages in a timely fashion is tricky, even if you're working with a well-established protocol. Itamar Shtull-Trauring introduces Python's Twisted framework for writing networked applications.

  2. Installing Oracle 9iR2 on Red Hat 9
    While Oracle's understandably proud of their Linux support, Oracle 9i is unsupported on the latest and greatest Red Hat. That doesn't mean it doesn't work, just that you'll have to do a little tinkering. Roko Roic demonstrates how to install Oracle 91R2 on Red Hat 9.

  3. Connecting to the IPv6 Internet
    IPv6 is coming. In fact, you can encourage its adoption by using it right now, if you've already configured your Linux machine for IPv6. Ibrahim Haddad explains how to connect to the IPv6 Internet with Linux.

  4. Five Tips for a Better sendmail Configuration
    Using the vendor-configured version of sendmail bundled with your Unix OS may seem like the easy route to take, but Craig Hunt, author of sendmail Cookbook, says don't be fooled by this apparent simplicity. Creating a custom sendmail configuration gives you better performance, reliability, security, and maintainability. Craig offers five tips to building a better sendmail configuration.

  5. Using PHP 5's SimpleXML
    Unless you've worked with SGML, you may find it ironic that XML can be hard to parse. Most choices boil down to event-based parsing, bulky tree-walking, or writing more XML. The upcoming PHP 5 has another option, SimpleXML, that can take the pain out of simple and common XML uses. Adam Trachtenberg explains.

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