Hetzner EQ4 Xen Server Routing Problem with own subnet

July 28th, 2011 by admin | Permalink

I ran into the problem that I couldn’t get my DomU’s on a Hetzner EQ4 to connect to the internet.

Unfortunately this is because of the strange network settings Hetzner is using. There is a German manual how to set up a XEN server in their environment, but it is missing one really important part. Hetzner limits the access on their network equipment to the MAC address of your server. Hetzner is not giving you the possibility to set / create new MAC addresses for subnets.

Assuming you are using Debian Squeeze and your server is already set up, you will have to set a point to point connection in the Dom0 and each DomU.

DomO has the regular ip 178.x.x.x and one from the subnet 88.x.x.x – gateway is 178.x.x.1.
Edit the /etc/network/interfaces and add pointtopoint 178.x.x.1 after gateway. This should be the same ip address as your gateway.

For the routing you need one ip address of your subnet on the Dom0 installed. This will also be your default gateway for all DomU’s.

Add the default gateway as a pointopoint connection on every DomU and it should work.

Don’t forget to restart network or reboot the machine and instances.

Checkpoint secure client on Mac OS Lion

July 27th, 2011 by admin | Permalink

Good news! Same trick as described on my post about Checkpoint secureclient and Mac OS X Snow Leopard works on Mac OS Lion. So no worries when upgrading.

Founders at work – a book recommendation

July 26th, 2011 by admin | Permalink


This book is already a couple of years old, but for me it is still an inspiration from time to time.

The full title is Founders at Work: Stories of Startups’ Early Days (Recipes: a Problem-Solution Ap) and it is basically about the early stage of a couple of big IT companies such as Adobe, Apple, hotornot.com, Hotmail, Paypal or Yahoo!. To see how most of them developed from a small company in a garage to a multi-million dollar company is quite amazing.

How TripAdvisor is structuring their technology and teams

July 22nd, 2011 by admin | Permalink

I just found this interesting guest article of Andy Gelfond (VP Engineering at TripAdvisor) on highscalability.com.

He is describing how they are solving daily issues as well as showing how they are working within teams. Quite interesting for everyone interested in high traffic projects.

You can find the article on http://highscalability.com/blog/2011/6/27/tripadvisor-architecture-40m-visitors-200m-dynamic-page-view.html

A simple way to speed up your website box.js

July 18th, 2011 by admin | Permalink

Just found an article about a new “autoloader” tool for JavaScript called box.js.
It seems super simple and only loads the javascript code needed on a page. Will test it in one of my new projects and update this post.

Waiting for the Lion to come out of his cage

July 14th, 2011 by admin | Permalink

Rumours say Apple is about to release the next version of Mac OS X called Lion TODAY.

To be honest I can’t wait to see what Apple has developed the last two years on.

Common Apple, released the next cat.

Solved! Checkpoint SecureClient on Mac OS X 10.6 Snow Leopard

June 20th, 2011 by admin | Permalink

Unfortunately, the SecureClient from CheckPoint doesn’t support 64bit environments. Nearly every Mac you can buy today supports 64bit as default. Brings a lot of benefits, but thats a whole other topic. So, the CheckPoint client currently only works in 32bit Snow Leopards.

There is two ways to achieve that.

Default boot into 32bit. This is described in the Knowledge Base entry on the Apple page here: http://support.apple.com/kb/HT3773

Second: Press 3 + 2 while booting up the system. Guess which key combination you have to press if you want a 64 bit system!?

Hope that helps.

Setting up a VPN Server on Mac OS X 10.6 >

April 26th, 2011 by admin | Permalink

I was just looking around for a possibility to connect to my computer at home secure thru a VPN. Unfortunately my router at home has no VPN feature implemented. As with most broadband packages, you get the cheapest router possible from your ISP. In my case I rely on the router as I get my television signal thru my internet connection and the router works as an authentication device for the media box from my ISP.

Anyway… I found a pretty exciting tutorial about setting up a VPN server on a Mac OS X machine on theilluminatedengineer.com.
Took me about 10 minutes to set it up and have it up and running.

Pretty thrilled by node.js

April 13th, 2011 by admin | Permalink

How could I have missed that?

node.js is an evented I/O for Google V8 engine.

Okay, so what does that mean?
Basically it means it is a library on top of V8 that enables you to do things with JavaScript that haven’t been possible before. Things like coding and running your own webserver or tcp server. As nodejs never stops running processes it can do several things at the same time. Like running the webserver and doing calls to another webserver at the same time, for several users and without running more than one process.

To be honest it is easier if you just watch this video. It’s worth watching!

Update on hacking PHPList to redirect subscription and unsubscription page

April 13th, 2011 by admin | Permalink

About 4 years ago I wrote a post about hacking PHPList to redirect the subscribe and unsubscribe pages. It is one of the most read articles on my blog. And has around 50ish comments right now. It seems like there is still a high demand for a solution.

I didn’t do much work with PHPlist since then, but from looking at the current version 2.10.13 I would assume the following works.

Please be aware that this is totally untested and just a guess. So if anyone could test this and comment here, I would appreciate it.

Code has changed a lot since I have downloaded the project the last time. There are now functions instead of spaghetti code. To be fair, there is still a lot of spaghetti code. Anyway I still think PHPList is an awesome product. Especially as an open source solution.

Seems like the structure is till the old one. All main functions are located in lists/index.php.

For the subscribe page go to line 404 and look for:

function subscribePage($id) {

This leads you to the function that is generating the subscribe page.

Looking for the line 525 there is a

return $html;

Remove that line and replace it with a

header("Location: YOURURL.com");

For the confirmation page go to line 528:

function confirmPage($id) {

Look for return $res; in line 580.

Comment it out or remove it and replace it with the header redirect.

Finally go to line 583 for the unsubscribe page.

function unsubscribePage($id) {

You will find in line 700 the

return $res;

Same procedure here.

This is only working if PHPlist is not writting a header up front.

As I mentioned in the beginning, TOTALLY UNTESTED NO GARANTUEES.

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