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Monthly Archives July 2011

Validating IP Addresses

I’ve been working on a fix to a system script that passes around and manipulates IP addresses. With IPv6 becoming more prevalent this script must work with IPv6 addresses not just v4. While working on this and digging around the web I ran across some stuff that I think is worth sharing. The first thing [...]

Posted 19 July 2011 † Philip § Computer ‡ Comments (0) ° Tagged: , ,

Understanding Multi-Level Security part 4

In my last post on this topic, we got into what I would consider the second half of Multi-Level Security (MLS). Here we discussed categories, also known as compartments and how they relate to the security model itself. We then extended the short-hand logic adapted from Chu and Older to allow for reasoning through access [...]

Posted 14 July 2011 † Philip § Computer ‡ Comments (2) ° Tagged: , ,

Ethernet Bonding on Debian Squeeze

Spent a few minutes searching for a howto for setting up ethernet interface bonding on a new file server I’m building today. Nothing special but I found a bunch that aren’t that great … I know, welcome to the internet right? But I did find one that’s awesome from tuxhelp.org. My final config went like [...]

Posted 12 July 2011 † Philip § Computer ‡ Comments (0) ° Tagged: , ,

Exim + Sieve issues

I spent much longer than I’d like to admit moving my mail server today. The Debian exim4 package is very easy to configure and setting up TLS and authentication is a snap with the help of a very good Debian Administration article. Also I’ve had to tweak the address_file transport to support Sieve and the [...]

Posted 10 July 2011 † Philip § Computer ‡ Comments (0) ° Tagged: ,

Understanding Multi-Level Security part #3

There are two parts to a Multi-Level Secuirty (MLS) policy. Now that we’ve covered the sensitivity component it’s time to address the second component which is typically referred to as a category or compartment. Before we get into the rules that govern this policy component however, let’s talk about why we need them. Sensitivities are [...]

Posted 03 July 2011 † Philip § Computer ‡ Comments (1) ° Tagged: , ,