CentOS set static IP address

To set a static IP address in CentOS edit the file
/etc/sysconfig/network-scripts/ifcfg-$networkcard
Where $networkcard is the name of the interface that you want to setup.
The default is dhcp so you have to change like this, for example:
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
IPADDR=192.168.8.3
NETMASK=255.255.255.0
GATEWAY=192.168.8.9
DNS1=192.168.8.203
DNS2=192.168.8.213
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
UUID=aabb3fe2-4eea-4096-9dbb-a674e196a821
DEVICE=enp1s0
ONBOOT=yes

Change default audio track/subtitles on mkv files with mkvtoolnix

First thing, have a look at the properties of the mkv file that you’re going to edit.
You can use mkvinfo but i prefer Mplay, it’s more clear.
Just open the file and with a right-click you can see the list of the audio tracks and subtitles.

Choose the default audio track that you want and take note of the track number (let’s image you want the 3rd one).
Now set the default flag for that track to 3 and the others to 0:
mkvpropedit filename --edit track:a1 --set flag-default=0 --edit track:a2 --set flag-default=0 --edit track:a3 --set flag-default=1

Do the same for the subtitles (set everything to 0 to disable subtitles):
mkvpropedit filename --edit track:s1 --set flag-default=0 --edit track:s2 --set flag-default=0