Stuff Jos van der Woude cares about

Summary

Goal: Create both primary and (backup) secondary DHCP and DNS services in a small home network.

Needed: one Linux server, one Windows machine and one DHCP capable router with a telnet interface.

Assumption: some programming experience.

Contra indication: not necessary when two Linux servers are available.

Alternative option: Dual DHCP DNS server, sourceforge.net/projects/dhcp-dns-server/files/.

Note: IP addresses, domain names, user names and passwords used here, do not reflect the actual setup.

Overview

My home network consists of one server running Linux, a number of wired clients running on Microsoft or Apple operating systems and an seemingly ever growing number of wireless clients running on a variety of platforms. The network infrastructure consists of a managed switch, a dual WAN router with wireless AP, a separate second wireless AP, a cable modem and a ADSL modem. The server is running both ISC DHCPD and ISC Bind providing crucial DHCP and DNS service to clients in the network.

The goal is to design the network in such a way that when the server is down (for whatever reason) Internet service to known clients is not interrupted. Specifically, known clients are still able to receive DHCP leases and resolve private domain names to IP addresses and vice versa. Obviously other services the server may provide, e.g. smb shares, are interrupted.

To achieve the stated goal it is necessary to have secondary DHCP and DNS services in case the primary services on the Linux server fail. Figure 1 outlines the design.


Figure 1 DHCP and DNS services and their backups

Read whole article for the details of the setup.

Saturday March 24th I attended the concert "Pure Passion" of the vocal group Cantatrix in the St. Willibrod Church in Utrecht. To hear Cantatrix sing is always a pleasure; this time it was even more special because of the location. I have lived in Utrecht for many years, but the Willibrod Church was new to me.




The St. Willibrord Church in Utrecht is one of the best preserved examples of the Utrecht School of the Gothic Revival. The church is almost invisible in the surrounding buildings, but who enters is immediately struck by the overwhelming impression of this mystical ornate church, built by architect Tepe and the St. Bernulphusgilde.

During the concert I shot a series of publicity photographs. This was quite challenging due to the low light conditions in the church.

Occasionally I come across a not so recent movie and think 'How come I didn't know about this movie?' The Fall (2006) is just such a movie. I read about it in a photography forum, checked it out on wikipedia and went and ordered the blu-ray in an online store. I was in awe. Yes, the story is good and quite sophisticated. But the imagery and cinematography is simply unique, in a class of its own. Not only was the film made without any computer generated imagery, but it was filmed in twenty or so different countries. Obviously twenty very, very special places.



So who made this film?

The answer is Tarsem Singh Dhandwar. This is a guy who made his fortune filming some of the best TV commercials. You will know them when you see them: Nike, Pepsi Cola, BMW and the likes. Apparently he went all over the world to film these commercials and the very special places he visited stuck in his mind. A dozen or so years later he made the Fall. Since nobody wanted to sponsor a commercials director wanting to make this movie, he funded the whole enterprise out of his own pocket. Some of the other movies Tarsem made are: The Cell (2000), Immortals (2011) and Mirror Mirror (2012). I am sure The Fall will achieve cult status. Yes, it is that good in my opinion. A very motivated fan created a website with (nearly) all the Fall locations.

Awesome!

I use Lightroom to keep track of my 56.000 odd photos. It does an excellent job at that. Today Adobe released version 4.0 of their flagship photo management software. This is exciting news. Why? Check out the new Map module for starters!

Years of painstakingly adding GPS coordinates to my photos finally visually pays off. I love this mapping feature.

In case you are wondering about some of the dots. My GPS tracker works just fine when I am sitting in a plane heading for the USA.