In openSUSE is easier. Everything can be done under YaST.
1. Open YaST and go to Network Devices>Network Settings.
2. Then choose Statically Assigned IP Address (move with tab button and click on space button). Give the static IP you want (IP address needs to be in the same range as the router's) and as Subnet Mask, 255.255.255.0. Press Next (press enter).
3. You'll see an overview of the ethernet card.
4. Go to Hostname/DNS and add Google's DNS servers (optional).
5. Next, go to Routing and add your router ip (usually 192.168.1.1).
Now press OK, reboot and try to login again with SSH.