GNU/Open source

MAC Filtering (layer 2 address filtering) refers to a security access control methodology whereby the 48-bit address assigned to each network card is used to determine access to the network. Iptables, pf, and IPFW can block a certain MAC address on a network, just like an IP. One can deny or allow from MAC address like 00:1e:2a:47:42:8d using open source firewalls. MAC address filtering is often used to secure LAN or wireless network / devices. Is this technique effective?

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Debian version 5.0 has been released. It is recommended that you upgrade the system to latest version. Upgrading remote Debian server is a piece of cake. In this tutorial, you will learn about upgrading Debian Linux server from Etch to Lenny over ssh session.

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tail is one of the best tool to view log files in a real time (tail -f /path/to/log.file). The program MultiTail lets you view one or multiple files like the original tail program. The difference is that it creates multiple windows on your console (with ncurses). This is one of those dream come true program for UNIX sys admin job. You can browse through several log files at once and do various operations like search for errors and much more.

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Another clueless woman has claimed that Dell computer and Ubuntu Linux have kept her from going back to school via online classes. According to a story – a woman bought a Dell computer and realized she ordered it with the Ubuntu Operating System rather than MS-Windows. She tried to change OS to Windows but Dell refused. Her Verizon High-Speed Internet CD won’t load, so she can’t access the internet. She also can’t install Microsoft Word, which she says is a requirement for MATC’s online classes. As a result, with no internet and no Microsoft Word, Schubert dropped out of MATC’s fall and spring semesters. The full story is here including followup.

Now, I’ve no idea about Verizon’s modem and DSL connection but most A/DSL provider modem (router) comes with an Ethernet port. There is no need to use wizard or CD based installer. Other software such as MS-Word can be replaced with OO (I submitted all my school work using OO office writer and no one noticed the difference… ). Further both Verizon and MATC ready to help:

Verizon says it will dispatch a technician to try to assist her accessing the internet without using the Windows-only installation disk.

MATC also says it promises to accept any of Schubert’s papers or class documents using whatever software she has installed.

So what is the problem here?

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openoffice

Mail merge is a software function describing the production of multiple documents from a single template form and a structured data source. This helps to create personalized letters and pre-addressed envelopes or mailing labels for mass mailings from a word processing document which contains fixed text, which will be the same in each output document, and variables, which act as placeholders that are replaced by text from the data source. The data source is typically a spreadsheet or a database which has a field or column matching each variable in the template. When the mail merge is run, the word processing system creates an output document for each row in the database, using the fixed text exactly as it appears in the template, but substituting the data variables in the template with the values from the matching columns.

This technique of merging data to create mailshots gave rise to the term mail merge. OpenOffice.Org has a in built software mail merge feature.

If you haven’t tried OpenOffice.org’s mail merge feature because you find it confusing or difficult to use, you are in luck. Mail Merges in OpenOffice.org and StarOffice provides a detailed description of the mail merge feature from start to finish. Among other things, it shows how you can use the mail merge to create letters, labels, and envelopes.

=> You can download this excellent PDF ebook for your persusal or read the article online – Mail Merge in Openoffice.org: Everything You Need to Know.

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Linux / BSD and UNIX like operating systems includes software from the OpenSSL Project. The OpenSSL is commercial-grade, industry-strength, full-featured Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as general purpose cryptography library.

The Google security team discovered a flaw in the way OpenSSL checked the verification of certificates. An attacker in control of a malicious server, or able to effect a “man in the middle” attack, could present a malformed SSL/TLS signature from a certificate chain to a vulnerable client and bypass validation.

This update has been rated as having important security impact on FreeBSD, all version of Ubuntu / Debian, Red Hat (RHEL), CentOS, Fedora and other open source operating system that depends upon OpenSSL.

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VirtualBox is a virtual emulator like VMWare workstation. It has many of the features VMWare has, as well as some of its own.

I really like new Opensource VirtualBox from Sun. It is light on resources. Here is a quick tip – you can convert a VMware virtual machine (image) to a VirtualBox machine (image) using qemu-img utility, without reinstalling the GUEST operating system

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