News items for tag web - Koos van den Hout

2015-07-24 Less flash but still playable audio 2 years ago
I like to sometimes add audio to items here on my homepage. In a format accessible for anyone with both download and play in browser options. Until now this was done using a flash-based player but lately flash has not been the secure option.

With the latest browsers it is quite possible to have an html5 audio player, but to keep it accessible for every visitor I also want to keep the flash audio player available. So I looked up how to do that and found Using HTML5 audio and video.

The linked audio is also available as attachments to the homepage RSS feed which is the standard for podcast feeds but since the recordings of satellite passes don't have an audio explanation or introduction they are not very usable as a podcast feed.

Tags: , , ,
2015-05-04 Keeping PHP to a minimum 3 years ago
I noticed the recent upgrades left some PHP scripts non-working. The default is now to disable PHP in userdirs, via:
    # To re-enable php in user directories comment the following lines
    # (from  to .) Do NOT set it to On as it
    # prevents .htaccess files from disabling it.
    <IfModule mod_userdir.c>
        <Directory /home/*/public_html>
            php_admin_value engine Off
I decided I want some PHP in userdirs, but while I was working on this configuration I want to turn the default around: disable the PHP engine in the global configuration and only enable it on those sites where I need it for the site. So now /etc/php5/apache2/php.ini has:
; Enable the PHP scripting language engine under Apache.
engine = Off
And some sites that need it have in the VirtualHost config:
# enable php
    php_flag engine 1
    <FilesMatch "\.ph(p3?|tml)$">
        SetHandler application/x-httpd-php

Tags: , ,
2015-03-27 Overly interested Amazon EC2 nodes 3 years ago
On Camp Wireless and The Virtual Bookcase I see the following pattern in the access logs:
2620:108:700f::36bc:aade - - [27/Mar/2015:13:27:11 +0100] "GET / HTTP/1.1" 302 298 "-" "curl/7.36.0"
2406:da00:ff00::36e2:d963 - - [27/Mar/2015:13:27:38 +0100] "GET / HTTP/1.1" 302 298 "-" "curl/7.36.0"
Constant requests, 2 or 3 per minute from Amazon EC2 IPv6 addresses just requesting the / using curl. Over the day I now see 1334 unique addresses with at most 5 requests from one url.

The same pattern as described in Stange stream of HTTP GET requests in apache logs, from amazon ec2 instances - Server Fault with no real answer to the why.

It's not a problematic amount of traffic, I'd just like to understand what is happenning!

Tags: , , , , ,
2015-03-23 Meer mobiel geschikte pagina's 3 years ago
Recent gaf google me allemaal meldingen dat mijn websites niet goed zouden werken op mobiele apparaten (telefoons, tablets). Het gevolg is dan dat google bij zoeken vanaf mobiele apparaten de sites ook minder aantrekkelijk zou vinden.

Mijn eerste gedachte was dat dat me niet zoveel uitmaakt omdat de gemiddelde bezoeker van mijn sites wel vanaf een desktop of laptop PC komt. Maar aan de andere kant doe ik simpele dingen ook vaker vanaf een tablet tegenwoordig en zag in ieder geval mijn homepage er daarop niet uit. En sites als Camp Wireless hebben zeker een mobiel publiek.

Alleen liep mijn kennis wat achter. De laatste keer dat ik serieus keek naar sites voor mobiele devices was toen WAP de oplossing was. Dus maar eens de informatiepagina's gelezen die google aangaf, over viewport gebruik en media queries voor CSS.

Voor de meeste sites is het een simpele CSS aanpassing om een en ander mogelijk te maken. Onder een bepaalde breedte hebben de 2 kolommen die ik vaak gebruik niet zoveel zin. Dus met de media query dit opgelost. Nu langzaam maar zeker sites aanpassen. En van sommige sites moeten echt dingen aangepast worden (juist camp-wireless..) omdat daar nog deels verouderde technieken gebruikt worden die aanpassingen voor mobiel moeilijk maken.

Tags: ,
2015-02-23 Preparing for upgrades and testing speed improvements for my homepage 3 years ago
As part of a needed upgrade on my homeserver I will also have to deal with Apache 2.4 and the changes needed there. Because some other things will change completely like asterisk I used an old server with comparable packages to do the same upgrades and test the results.

As keen visitors to my page may have noticed I am interested in the performance. This test-setup also gives me room to experiment with some possible new methods. I have to establish a baseline on that server first since it has different hardware.
Read the rest of Preparing for upgrades and testing speed improvements for my homepage

Tags: , , , ,
2014-11-24 Updates to my homepage 3 years ago
With some newsitems here on my homepage getting longer I started to feel the need to make a more blog-like format possible with items with an introduction and longer text. And titles here and there to give a better title to newsitems that deserve it. So some changes to the database format, support scripts and all the scripts generating pages.

The changes were big enough to update the version number so now it is 4.5.

Tags: , ,
2014-11-21 (#) 3 years ago
It seems I am a very special person for google: the 'Birthdays' calendar which should be filled with the birthdays of all people in your google+ circles had the option to remove it from the list of calendars or unsubscribe totally. After being on the receiving end of some rants about this it is clear a lot of people don't have the option to get rid of this calendar. I found a possible workaround: How to delete the Birthdays Calendar from your Google Calendar.

Update 2014-11-28: I was happy too early: now the calendar is back (without me asking for it) and I can't disable it normally.

Tags: ,
2014-09-02 (#) 3 years ago
Lag in DNS changes: I stopped hosting a domain for someone, the last 'regular' traffic was on 20 August 2012. But some web robots have a memory of their own, the last access by a search bot was 25 October 2013.

Tags: , ,
2014-08-04 IPv6 visitor stats 2014 3 years ago
Time to count IPv6 visitor percentage to different websites again:
SiteJuly 2009July 2010July 2011July 2012July 2014 my homepage 1% 2% 2% 3% 4% hcc!pcgg netwerkgroep 2% 2% 2% 3% 1% weather maps < 1% 5% 6% 7% 6% BBS files 1% 1% 1% 3% the webcam < 1% 1% < 1% 2% 2% The Virtual Bookcase < 1% 1% 1% 4% 87% Camp Wireless < 1% 1% 1% 3% 70% Weather station Utrecht Overvecht 1%
Interesting numbers. Results for The Virtual Bookcase and Camp Wireless are totally skewed thanks to some IPv6 bot constantly checking the site from constantly changing IPv6 addresses .. but without privacy extensions enabled.

Method: unique IPv6 addresses seen in the whole month / total unique addresses seen in the whole month.

Tags: , , , , , ,
2014-07-28 (#) 3 years ago
Somebody at was trying at a very high speed to brute-force /wp-login.php for one site on my server. The downside was that there was no /wp-login.php or any part of wordpress to brute-force, but that did not seem to deter the attacker. A temporary firewall rule now rejects all attempts.

Update 2014-07-31: Next load of attempts from And looking back in the logs shows other similar attempts.

Tags: , ,
2014-02-06 (#) 4 years ago
The webcam image at is getting popular at the moment due to the use by peaking at 0.5 requests/second.

Since the image is imported from a different server in a proxying setup this was causing quite some traffic on my adsl line. The image doesn't update every second, so I had a look into caching possibilities with apache 2.2. I wanted to use the memory cache for just this one object but I started with the disk cache because it's easier to debug and see the files on disk. This didn't work, and I could not figure out why. I followed the instructions found in apache2 - Apache Reverse Caching Proxy - why isn't it caching? - but still no caching happening.

I set up a separate virtual server with the logging set to level 'debug' and found the following interesting line in the log:
[Thu Feb 06 16:24:59 2014] [debug] mod_cache.c(370): (12)Cannot allocate memory: cache: Cache provider's store_body failed!
This looked more like a memory cache problem than a disk cache problem. But the memory cache wasn't configured at all. I decided to remove the memory cache support completely and that fixed things with the disk cache. The debug log suddenly had the right messages:
[Thu Feb 06 16:25:59 2014] [debug] mod_cache.c(633): cache: Caching url: /camwindow.jpg
Now the webcam image is cached for 120 seconds. Which saves some traffic on the ADSL line.

Update 2013-02-10: Requests still going at about 0.5 requests/second at busier times. The proxy reduces the impact on ADSL traffic and ping delays.

Tags: , ,
2014-01-31 (#) 4 years ago
Mooie tekst van Arnoud Engelfriet op Wat nou als jailbreaken mijn telefoon juist veiliger maakt? - Ius Mentis:
Overigens erger ik me wezenloos aan de trend om dienstverlening ‘producten’ te noemen. Een product doet pijn als het op je tenen valt. Mobiel Bankieren (of gratis reizen buiten de spits) doet dat niet, dus is het geen product.

Tags: ,
2013-12-18 (#) 4 years ago
Using SSL should secure your services, but it needs to be configured correctly to avoid several attacks and keep the chances low that third parties can decrypt the traffic. With the SSL Server test from Qualys SSL Labs you can check the intimate details of your https SSL configuration.

And when you wonder what to use to improve your score when using Apache mod_ssl, here is a configuration snippet shared by the right people at Tilburg University:
SSLEngine on
SSLProtocol all -SSLv2
# advies Wessel Dankers kub
SSLHonorCipherOrder on

Tags: , , ,
2013-12-18 (#) 4 years ago
Recently I had a security incident where a site was flagged as hosting malware but it took quite some searching to find the actual source of the problem. Access with a windows webbrowser with Avast security gave a big fat security alert mentioning 'js-hideme-h trj'.

I couldn't find the offending code until I checked the site with Sucuri SiteCheck website security scanner which found:
Known javascript malware.
t='';}}x[l-a]=z;}document.write('<'+x[0]+' '+x[4]+'>.'+x[2]+'{'+x[1]+'}</'+x[0]+'>');}dnnViewState(); 
This is a bit of obfuscated javascript code. Some more searching found the full code:
autson javascript
Sorry about the inline image for this code but I found out some virus scanners don't like even the text version of this javascript code. Also available: autson javascript obfuscated css. When your virusscanner stops you from accessing that javascript: look for a virusscanner that doesn't protect your browser from code which wants to mislead search-engine bots.
To run this bit of code in spidermonkey I need to change the document.write to print and test it:
koos@vm-u-04:~$ js test.js
<style undefined>.dnn{position:absolute;top:-9999px}</style>
Now that is CSS (cascading style sheet) code to hide a bit of page from the browser (outside the viewport) and this is indeed a sign of evil SEO (search engine optimization) tricks happening. There was only one link after that bit of css, and it was:
<p class="dnn">By A <a href="" title="web design company">Web Design</a></p>
Which indeed uses that CSS class dnn. A websearch for '' found me Malicious Joomla Extensions which explains the problem more clearly and shows that in a different version of the extension the code to be shown is fetched from a server which means even worse code can be included.

Be careful with your joomla (or other CMS) plugins.

Tags: , ,
2013-10-28 (#) 4 years ago
I found out the Using Dynamic DNS for your dynamic IP micro-howto didn't render correctly as it was using ISO-8859-1 as character set while the webserver for has been configured to give UTF-8 as default character set. This howto is generated using DocBook so I dug into the bit of config.xsl where this was set and found after some searching that there is a config variable for the html 'chunker' named chunker.output.encoding which was easy to set:
<xsl:param name="chunker.output.encoding">UTF-8</xsl:param>
For 'html-nochunks' it was a bit harder until I found Output encoding in docbook which has the right bit of code:
<xsl:output method="html"
And now the Using Dynamic DNS for your dynamic IP micro-howto and Draadloos netwerk uitleg en installatie look correct again.

There may be other (older) html documents on this server with other character set breakage.

Tags: ,
2013-09-12 (#) 4 years ago
Netflix is eindelijk beschikbaar in Nederland. Gisterenavond eens geprobeerd. Toen ik gisterenavond het apps menu van de smarttv opzocht wilde deze gelijk een update en daarna stond netflix vooraan in het rijtje apps.

We hadden een hoop series in gedachten die we wel on-demand zouden willen kijken. Het hele rijtje (Bones, Ice Road Truckers, Big Bang Theory, Game of Thrones, The Newsroom, Law and Order) was allemaal niet beschikbaar. Ik hoop dat het aanbod vooruitgaat.

Veel (alles?) wat er staat aan engelstalig materiaal is in het nederlands ondertiteld. Een onduidelijkheid in de interface is dat de score van programma's wordt gegeven op een schaal van 1 tot 5. Normaal voor amerikanen, raar voor nederlanders.

Bladeren/zoeken ging vlotter op een PC met toetsenbord/beeldscherm dus daar hebben we uitgezocht wat ze dan wel hebben. De keuze viel op Frozen Planet.

De standaard kwaliteit viel tegen op een full-hd tv. Dus toen in de voorkeuren gekozen voor de hoogste kwaliteit. Dat zag er stukken beter uit. Tijdens het afspelen zo nu en dan gekeken wat er aan data binnen kwam stromen: 4 tot 6 mbit.

Tags: , ,
2013-09-03 (#) 4 years ago
Bladerend op het web kun je soms prachtig verdwalen en grappige dingen ontdekken. Zo zocht ik op een overzicht van amateur radio repeaters in Oostenrijk volgens de Oostenrijkse radio-amateur vereniging (engelstalig) en kwam daar ook de zoekmethode op de Duitse radio-amateur website tegen met lijst amateur radio repeaters in Oostenrijk verzameld door DL3EL (duitstalig) waar ik via de repeater in Fiss de website van Österreichischer Versuchssenderverband, Landesverband Tirol, OE7 tegen kom dat ze ook een Hafelekarhütte Österreichischer Versuchssenderverband, Landesverband Tirol, OE7 hebben, dus een berghut waar je als radio-amateur kunt verblijven en verbindingen kunt maken. Een voor mij onverwachte combinatie, maar bij verder nadenken niet heel vreemd. Hoge locaties kunnen interresante voordelen hebben voor de radiohobby.

Meerdere van de repeaters op de bovengenoemde lijsten staan trouwens op skilift installaties. In Oostenrijk zijn dat natuurlijk plekken waar hoog infrastructuur is voor repeaters. Andere repeaters in Oostenrijk hebben zonnepanelen voor de stroomvoorziening.

Tags: , ,
2013-02-13 (#) 5 years ago
The number of items in the database behind this homepage passed 2000. The item which should be number 2000 is Wardriving results up to today: 2126 new networks with GPS locations - 2013-02-11. Lots of subjects have passed. Notable is the rise in the amount of posts: I have posted more items (and more text) in 2013 already than in the whole of 1999 although I think the newsitems from a file only started in September 1999 which in February 2006 switched to a postgres database.

Tags: , ,
2012-09-28 (#) 5 years ago
I found IPvFox, a firefox extension which lists all servers involved in a page and their IPv6/IPv4 addresses. The use-case is seeing how much of those use IPv6, but it's also interesting to see how many hosts are involved in a webpage. With images, frames, scripts which can all come from different places some pages have interesting dependencies. From a few sites which I tried the one which had the most servers involved turned out to be CBC North with 23 servers. With a few dual-stack servers, including a trackingserver for visual revenue, a company measuring web traffic for media companies, who seem to be interested in IPv6 traffic measurements.

Update: There is one detail.. as stated on the webpage:
IPvFox provides a panel listing the hosts from which the current page and its resources were loaded.
So this is interesting in an environment with outside IPv4 and IPv6 connections. When I use a proxy which can be connected via IPv6 the display gets very boring: the address of the host from which the resource was loaded is always the IPv6 address of the proxy.

Tags: , , ,
2012-08-03 (#) 5 years ago
Time to count IPv6 visitor percentage to different websites again:
SiteJuly 2009July 2010July 2011July 2012 my homepage 1% 2% 2% 3% weather maps < 1% 5% 6% 7% hcc!pcgg netwerkgroep 2% 2% 2% 3% BBS files 1% 1% 1% the webcam < 1% 1% < 1% 2% The Virtual Bookcase < 1% 1% 1% 4% Camp Wireless < 1% 1% 1% 3%
Interesting numbers. Websites with a more 'general' audience are now also growing this year.

Method: unique IPv6 addresses seen in the whole month / total unique addresses seen in the whole month.

Tags: , , , , , , , ,
⇐ Newer news items for tag web  Older news items for tag web ⇒
, reachable as PGP encrypted e-mail preferred.

PGP key 5BA9 368B E6F3 34E4 local copy PGP key 5BA9 368B E6F3 34E4 via keyservers pgp key statistics for 0x5BA9368BE6F334E4 Koos van den Hout
Other webprojects: Camp Wireless, wireless Internet access at campsites, The Virtual Bookcase, book reviews