Category: Linux

Linux: Anonymize IP logs with syslog-ng

By using a replacement for the default system logger, syslog-ng, you can selectively stop IPs from being written to log files, for example on a mail server.

Linux: Automatically shredding files before deletion

I am currently playing with the thought of [url=http://linux.die.net/man/1/shred]shredding[/url] files automatically before they are unlinked from the file system (for example on a mail server). I wrote a small library that you can inject...

Ubuntu is Tracking You: Disable connections to Canonical

Ubuntu not only connects to Canonical servers on request, it does so permanently in the background. It even transmits geolocation information for the weather applet. Here’s a quick fix that removes all components involved...

Howto: Enable Receive Packet Steering (RPS) on Linux 2.6.35

We run a high bandwidth Tor exit node on a Gbit connection. Unfortunately, the NIC by our hoster doesn’t support MSI-X to distribute interrupt load across all cores. The latest linux kernel 2.6.35 adds...

Remove IPs from Outgoing Mail (Postfix SMTP)

I use Postfix as SMTP server. By default, it includes every user’s IP and hostname in outgoing mails, even internal ones. As there is no need for the outside world to see what IPs...

Tor on Debian, self compiled for better Performance

According to the [url=https://www.torproject.org/faq.html.en#RelayMemory]TorProject FAQ[/url], a Tor relay will use less memory if compiled with openBSD-malloc and the latest openSSL. This helps if you’re resources are limited, or if you run a high bandwidth...

Lenny’s Xen Kernel 2.6.26 Causes DomU Freezes

With the release of Debian 5.0 “Lenny” as stable, I have upgraded my servers and installed its Xen 3.1.2 and Kernel 2.6.26 Xen packages for my DomU’s. After that, one of my DomU’s kept...