How to stop multicast packets flooding the wireless interface in dd-wrt

For some reasons, they don’t provide a simple GUI switch for this and their wiki page doesn’t have the correct commands.

Anyway, the way to do it is this:

Check what is your wifi interface. Go to status/Wireless and check the Interface field below (you need to connect at least one client). In the following example, we assume it’s eth1.

Go to Administration/Commands

Type the following (assuming your LAN is on the 192.168.1.x range):

insmod ebtables
insmod ebtable_filter
insmod ebt_pkttype
insmod ebt_ip
ebtables -A FORWARD -o eth1 -p ipv4 --pkttype-type multicast --ip-source ! 192.168.1.0/255.255.255.0 -j DROP

Press Save Firewall and reboot.

Voilà! No more multicast flooding of the wireless interface! This is handy if you’re using IPTV. As a bonus, normal multicasting on your LAN will still work (Samba, Homegroups, etc…)

Radioactivity

Because of the recent events at the Fukushima nuclear power plant, I got myself a Geiger-Müller counter (also known as dosimeter or radiometer).

Here’s some testing I did with it:

Those are background radiations. The range I usually get are from 0.07 μSv/h to 0.15 μSv/h.

Background radiations are what someone normally gets since everything around us is a bit radioactive. It mostly comes from cosmic rays and terrestrial sources. The unit used is the sievert (Sv). A microsievert (μSv) is 0.000001 sieverts. A milisievert (mSv) is 0.001 Sieverts. The counter displays how many microsieverts it gets per hour, so if for example you stay near a source of 1 μSv/h during 5 hours, the total radioactive dose you’d get would be 5 μSv. In this article I’m focusing on gamma radiations.

Normal background radiations shouldn’t exceed 0.30 μSv/h.

Dust has a tendency to gather radioactive particles. 0.19 μSv/h for a sample of dust that my wife didn’t find 🙂
Radioactive rock
I’m not sure what this rock is but it’s slightly radioactive.
Radioactive bench
No worries. It can still be used safely as a bench.

For now I didn’t detect anything abnormal during my testing, and I hope it stays that way. These readings were taken around Geneva, Switzerland. It seems someone is doing the same as me but in Tokyo.

The joke called DVB-T

DVB Logo

You can’t stop progress. When TV switched from Black & White to Color it was amazing. Now that the TVs are switching from analogic to digital transmission, a major step is done. See the following comparison:

Analog DVB-T
Resolution 720×576 720×576
Digital sound yes yes
Progressive (no interlacing) no no
Works with all antennas yes no
Reception with low signal yes no
Free MPEG image artifacts no yes
Channel switching delay none 2 seconds
Station transmission delay none 5 seconds

As you can see, DVB-T is clearly superior. You can’t stop progress.

Syobon Action

Syobon Action (also known as Cat Mario or Neko Mario) is a platform game with a similar gameplay experience as Super Mario Bros, except it’s more difficult and was written by a psychopath.

We improved the SDL version and made a Windows port.

Notable changes (see the README.txt in the archive)

  • fullscreen mode
  • improved sound quality
  • english translation
  • joystick support
  • bug fixes

Downloads:

Syobon Action for Windows (if you get a DLL error you need to install the VC2010 redistributables). Was tested on Windows XP, Windows Vista, Windows 7 and Windows 10.

Syobon Action for Linux/BSD/Unix (contains the source code, you need sdl, sdl_image, sdl_gfx, sdl_mixer and sdl_ttf to build it). If you want to help building distro specific packages (eg. deb) feel free to provide them. Many thanks to Christian Birchinger for testing and improving the build.

Dell Inspiron 9400 ATI x1400 driver

Update: this driver is reported to work under Windows 10

Since Dell is unable to provide a recent Catalyst release for its Dell Inspiron 9400 for Vista or Windows 7 and explicitly forbids ATI from distributing one, here it is.

Download Catalyst 8.12 for Inspiron 9400 (32-bit)

Note: The Inspiron 9400 is also known as Inspiron E1705 in some countries.

Catalyst 10.2 has a bug related to laptop panel scaling which is why I’m providing 8.12.

Street Parade 2010

On the 14th of August, held the Street Parade in Zürich with the many love mobiles and techno music. Unfortunately the weather wasn’t very great with a few rains from time to time. I didn’t find it very crowded at first but then people started to arrive. All in all an excellent event as usual.

N95 unlocking and battery extension

Following up on Vodafone’s inability to unlock my Nokia N95 I bought from them, I decided to use other ways.

First, there are tons of “online unlockers” websites who claim to be able to unlock phones but nobody explaining how they do it. I tried 2 of them and they weren’t successful, even though they advertise handling the N95.

The first one was E Distributions UK Ltd. They reimbursed my Paypal payment the same day with “unlock code cannot generate full refund”. Fair enough.

The other was a bit more problematic. I ordered an unlock code for my girlfriend’s LG KU990i from MobileUnlocked which is really Unlockingonline. After 2 days they claimed to have found the unlock code which was: “NO UNLOCK CODE”, which obviously was of no use for me. I complained to them asking for a refund and 2 days later they did so.

My guess is that those online unlockers probably work for older phones which have key generators available for them, but these companies also advertise that they can handle new phones for 2 reasons:

  • be indexed by search engines
  • be able to provide the service as soon as a keygenerator appears

Unfortunately this is just going to waste your time. You can try, but if you do make sure you always use Paypal as they have a reimbursement policy if the merchant fails to provide the service (make sure you keep copies of mails and website results).

I ended up unlocking both phones from a local store. No problems whatsoever.

Now on to fix one of the most annoying problem of the N95, and any modern smartphone: the limited battery life.

The N95’s original battery is a 950 mAh li-ion battery and has the amazing property of lasting about one day with moderate usage. Even worse, if you use your N95 to listen to some music, it dries out in 2 to 3 hours.

So I ordered a 2400 mAh li-polymere battery from mobiltec24. Unfortunately the phone was constantly switching itself off and crashing.. weird! I mailed them and they quickly sent a replacement battery which works fine so far. The phone lasts about 4 days with moderate usage, at last! This was the N95’s biggest problem and newer phones seem to have that problem as well. The battery is bigger and heavier (needs a modified battery cover, which is supplied) but the trade off is really worth it.

Voipbuster sucks

For years I used the services from voipbuster.com on my Nokia phone for international calls. They had good pricing and it worked fine.

2 days ago I had to make a call from my laptop. I went to their website and downloaded their VOIP client, which seemed to work ok.

Now comes the problem. Their client has an option to import contacts from MSN and Skype, the contacts appear in a list and you press ‘Ok’ to import them.

What the client doesn’t tell you is that it does the following in the background, without you noticing:

– sends a skype message to all your contacts with:

<your_voipbuster_login> wants to talk to you with VoipBuster!

get this free software to instantly communicate online with friends, family, coworkers or anyone you choose! click here to download VoipBuster to get started.

It also sends an email which is faked as coming from you (including the headers) with a similar content to all your MSN contacts.

Was it so hard to have a checkbox with “Invite friends to use voipbuster”? Why do they have to do that silently in the background?

Let’s see, voipbuster is owned by betamax.com, their website says:

Betamax was founded in 2005 in Germany by a group of marketing experts.

Marketing experts? More like a bunch of morons.

So that’s it. voipbuster.exe can be classified as a spyware, sending advertising spam without telling you.

Gnucash sucks

So I just tried Gnucash, the accounting software. After spending some time reading the docs on how it works, I started creating some accounts and populating them. Then I close the program and open it later.

There was an error parsing the file c:\users\zapek\gnucash

What the.. I try to open all 4 backup files it did.. Same error message. Great, so gnucash 2.2.9 cannot open files it writes itself. And all my work is lost.

I try with gnucash 2.3.5 then, which is marked as unstable. I create just one account to test, saves and it does a wonderful crash “error in sqlite3 blabla”.

Maybe I should just use a pen and paper.

Vodafone sucks

About a month ago, I switched from Telefonica to Vodafone because the former was starting to get expensive, 75 € / month for a 10 mbit/s link, and their uplink was only 300 kbit/s which is really annoying as I also upload stuff to my servers from time to time.

Anyway, so Vodafone sent me the following piece of hardware.

It’s an Huawei EchoLife HG553

At first, vodafone offer you to connect through their 3G network for free until the ADSL link is working. So far so good. Once the ADSL link was up, I switched to that.

But I experienced frequent problems with DNS queries, that is, from time to time I would get the famous “host not found” error, and from all my computers. I first thought that there was a problem with Vodafone’s DNSes so I changed them in my computers, but it didn’t work any better.

Strange! At the end I started to suspect that Vodafone might be filtering DNS requests on their network but I didn’t see why, as hosts like ‘mail.google.com’ or ‘mail.live.com’ failed all the time.

I called their (useless) hotline. They made me change the DNSes on my local machine, without results of course, then changed the DNSes in my router and rebooted it. Hum.. So they’re accessing the router eh? ‘mail.google.com’ resolved once after that.. Then it failed again. They seemed clueless about the problem. They also said something that got my attention: “when I’m pinging mail.google.com from your router, it works fine”.

All right.. How are they accessing the router? And most importantly how can they ping from it as the default web interface doesn’t allow you to do so.

I remembered I was once able to access the router through SSH using admin/admin. So I did that and to my surprise, it didn’t work! So they must have been tampering with my router since I got online?

So, after hacking around, this is how to solve the problem.

First, you need to reset your router to default settings. Turn it off, insert a pen into the ‘reset’ hole, turn it on, wait 10 seconds, turn it off, remove the pen.

Disconnect the ADSL link, you don’t want your modem to reconfigure itself and remove the admin account again. I’ll shortly explain how they do that.

Turn on the modem. Its IP is 192.168.0.1, the admin account’s login is ‘admin’ and its password is ‘admin’.

Go to the web interface using admin/admin then reconfigure what you need to. You’ll see that you have much more options available than with the vodafone/vodafone login. Don’t touch the ADSL stuff, it is preconfigured properly.

Here’s a list of a few stuff you might want to do:

  • Advanced Setup/NAT: Enable UPnP. This is useful for Peer 2 Peer applications or stuff like MSN Messenger, Skype, VOIP or file transfert in chat programs
  • Advanced Setup/DNS/Dynamic DNS. If you want to use services like dyndns.org to have your router available anywhere
  • Important: if you don’t want vodafone to reconfigure your router and remove your admin access as soon as you go online, go to Management/SNMP Agent and Disable it
  • Management/Access Control: Here you can disable vodafone’s ability to access your router from the WAN interface. Just turn off everything except ICMP on the WAN side, and enable everything for you on the LAN side
  • Management/User Management: Change the password of your admin account. support is used by vodafone and the password is ‘support’ as well. Their access only works for telnet and ssh, not the web interface

Now do a SSH to the modem (with the admin account). If you need an SSH client for Windows, I can recommend PenguiNet.

Type the following:

iptables -t nat -D PREROUTING_IN 1

And that’s it! The DNS screw up is gone. Now make sure you configure your computers to use some other DNS than your routers because it is bugged and doesn’t work properly. You can use the vodafone DNSes:

89.6.239.4 212.145.4.98

You can now plug your phone line into the router’s ADSL port. If you disabled the SNMP services, the router won’t be reconfigured and rebooted by vodafone.

There’s still a caveheat, though. You’ll have to type the iptables command everytime you reboot your router. I’m trying to find a way to change it permanently.

I wonder if the vodafone support people realize how silly it is to tell users to change their DNSes when the router will intercept the queries anyway… Oh well.. Big corporations…