IP multicast is an interesting technology. It’s main purpose is to
save network bandwidth as much as possible – traffic is sent to hosts
which asked for it only (as opposed to broadcast). On the other
side, you need smarter (manageable) switches and separate and
non-trivial configuration on both routers and switches. Even more
complicated it is when you try to make it work over VPN. Continue reading Multicast over “stupid” networks
This weekend I was thinking how to make my webcam connected to
OrangePI send a picture “on demand”. There are daemons (e.g. motion or
webcam-mjpg) which do this but they capture images even when you are not
watching and I wanted to avoid this. There are also projects (fswebcam)
which are able to take single picture, save it to disk and end. I just
needed to run it after http request and send back the image. Installing
full webserver with some kind of interpreter (php, lua,…) seemed to me
like an overkill. So I came to an idea to use inetd.
And this is how I did.
Continue reading Primitive webcam server using inetd and fswebcam
this post will be about my homemade IoT thermostat. The goal was to not install any cables (because I live in a rented flat), to go really cheap and to be able to set the temperature from anywhere. I’ll also give you some tips you should think about when building your own. Let’s get started.
Continue reading Yet another IoT thermostat
since I found, that Debian chroot on OpenELEC is not the best solution, I tried to do it vice-versa. This is what I needed to do.
Continue reading OrangePi: Installing OpenELEC chroot into Armbian
I have an OrangePi running jernej’s OpenELEC build connected to my TV. It works very well and stable, but on the other side, you can’t do much more with it because OE is very limited Linux distribution. This is a short guide how to run standard Debian services (nginx, samba, openvpn, … anything) in Debian chroot. Continue reading OrangePi: Installing Debian chroot into OpenELEC
I have a favorite cheap chinese router based on RT5350 (running OpenWRT).
Recently, I was wondering, why I can’t get WiFi on a few of them working. I have one piece running quite old (4xxx svn) OpenWRT where the WiFi works OK. So I tried to compile exactly the same version and install it on the non working piece. I also put the same wifi config there but nothing. It didn’t work. Continue reading Fixing non-working WiFi on RT5350
This is how to change default SSL key size on iDRAC Dell R415 Continue reading 2048 bit SSL key on Dell iDRAC R415
echo | openssl s_client -connect mail.example.sk:25 -starttls smtp | openssl x509 -noout -dates
Testing SPAM filtering from shell
echo "XJS*C4JDBQADN1.NSBN3*2IDNEN*GTUBE-STANDARD-ANTI-UBE-TEST-EMAIL*C.34X" | mail -s Spam_test email@example.com
Disable filtering for example.com
add following lines to /etc/amavis/conf.d/50-user (don’t forget the dot before domain, it has to be there):
@bypass_spam_checks_maps = (
@spam_lovers_maps = (