Understanding IP Proxy ARP

One of the somewhat confusing protocols in Layer 2 networking is Proxy ARP. Probably most of you already know how ARP works. In this post I will explain the principles behind Proxy ARP, and have a short look at the benefits and drawbacks. ARP Basics The Address Resolution Protocol is responsible to find the MAC… Read More »

Online Resize (non-root) Linux Partitions on VMWare Guests

Several VMs continuously need more HDD space, for example my BackupPC instance. For this reason I’ve put the actual data on a separate Hard Disk and partition, to allow an online-resize of the partition, if necessary. This article explains the procedure for Debian guest on a VMWare infrastructure, but it should work similar on other… Read More »

VMWare vCenter Appliance root Password Lockout

In our lab infrastructure we have two or three little ESXi hosts managed by a vCenter Appliance. A few days ago, suddenly root login was not possible anymore. Most of the other local accounts worked, however. My first thought was that someone changed the password and forgot to document that, however, no one lifted his… Read More »

Automated MySQL Database Backup for BackupPC

BackupPC is my preferred backup solution for quite a long time now, as it is relatively easy to set up and backup and recovery works like a charm. One tricky aspect is the automated backup of MySQL databases. With this post I would like to present my solution, which backs up all databases, stores them… Read More »

Atlassian Crowd and the Apache Connector

A short explanation first: personally, I really like the Atlassian products, such as Stash, Confluence, Jira and so on. I first got in touch with these tools at work, where we use them exclusively when developing software, the Confluence Wiki Software also for documenting network things.  In my free time, I do some PHP Software… Read More »

Push full GIT repository to new origin / remote

Having a local GIT repository linked to a remote which is not existing anymore is a problem I faced multiple times in the last time, so I thought I should document this. The steps are as follows: Identify old non-existing remote and delete it Add new remote Push all branches Step 1: Identify…

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Category: GIT

Cisco ASA Management access from VPN

During my study for the Cisco FIREWALL v2.0 exam I came across an issue today. I am connecting to our lab via a Cisco firewall via IPSec VPN. However, I had to modify the ASA’s config from this remote session. The question now was, how to allow remote management from the VPN pool. The topology… Read More »

PHP __autoload() not working – Smarty in effect

This evening I came across a very annoying problem while coding for my PHP+MySQL project. I decided to move all extensions used in this project to a folder, called “extensions”. This folder now contained some files, all containing classes. Instead of writing many “include” or “require” commands, I decided to use the PHP built-in autoload… Read More »


With this first post I just want to welcome you on my new Blog. No doubt it is not perfect until now, but I will try my best to continuously improve it to provide many interesting posts. Stay tuned!