Debian GNU/Linux System Administration Resources

Simplifying repetitive Apache configuration with mod_macro

2015-12-09T12:34:40Z

Apache is one of the more flexible webservers, and most of this is achieved via the use of various extension modules bundled with it, or externally available. mod_macro is a great module allowing you to simplifying configuration of multiple virtual hosts enormously.

Enabling swap on debian based system

2015-12-08T18:01:55Z

Recently I found myself without a swap partition (having installed another OS and reworked my disk-setup) so I wanted to share a quick guide to enable swap again.

Offering IPv4-only services over IPv6

2015-11-29T08:06:53Z

Although IPv6 is clearly the way of the future there are some software services which only support IPv4 access. Here we'll show a simple approach to exporting them to IPv6-based clients.

Analysing performance problems with systemd

2015-09-26T18:06:21Z

Now that Systemd is the default init-system in fresh installations of Debian GNU/Linux it is worth highlighting some of the new features.

Validating SPF and DKIM at SMTP-time with exim

2015-08-04T07:58:50Z

In our recent articles we've discussed creating SPF-records to avoid spoofed mails, and the creation and setup for DKIM-signing emails, for a similar purpose. Here we'll look at the other side of the coin; performing DKIM and SPF testing on your incoming email.

Tying together SPF and DKIM with DMARC

2015-08-03T19:35:22Z

When it comes to increasing deliverabiity of email, and preventing spoofed/forged emails the preferred solution these days is DMARC, which allows the use of SPF and DKIM to be enforced for domains in a unified manner.

Avoiding mail-spoofing with SPF

2015-08-01T17:34:33Z

The Sender Policy Framework, or SPF, is an email-validation system which is designed to allow spoofed mails to be indentified. In this brief introduction we'll look at how you can configure your outgoing emails to take advantage of this validation.

DKIM-signing outgoing mail with exim4

2015-07-29T06:28:20Z

There have been several systems designed to prevent mail spoofing over the years, the two most prominent solutions are DKIM and SPF. Here we're going to document the setup of using DKIM to signing outgoing mails with Debian's default mail transfer agent, exim4.

Setting up a personal secure apt repository

2015-05-24T09:58:32Z

Packages under development aren't always ready to be in the main Debian archive. But that doesn't mean it should be hard for people to install them. When asking people to test programs, it is most convenient to present it in the

Preventing SPAM connections with bird.

2015-05-22T07:25:03Z

Bird is an Internet routing daemon with full support for all the major routing protocols. It allows you to configure hosts to share routing information, via protocols such as BGP, OSPF, or even statically. Here we're going to look at using it to automatically blacklist traffic from SPAM-sources.