The standard place on Linux for the network configuration is /etc/network/interfaces , but OSMC uses connman which is a lightweight network controller designed for embedded devices. Connman uses different files to the traditional Linux network configuration files. To define a static IP address one should create a config file in the /var/lib/connman directory with a filename ending with .config.
In my case I created a file: /var/lib/connman/ethernet.config
[service_ethernet] Type = ethernet IPv4 = 192.168.0.12/255.255.255.0/192.168.0.1 Nameservers = 22.214.171.124
This uses my local network settings (IP address/subnet mask/default gateway) and I’ve set the dns entry to one of Googles public DNS servers.
If you need something a bit more advanced (perhaps wifi with encryption) then more examples are available in the config-format.txt file on git.
I then rebooted the Raspberry Pi and it came up with the new IP address (the changes can be applied dynamically, but I prefer to reboot whenever making network changes to make sure that they come up correctly at start-up).
From – http://www.watkissonline.co.uk/wordpress/?p=7691