cannot create static ip address

I don’t understand how to create a static ip address. I just use a residential router/modem gateway device. It assigns ip addresses in 192.x.x.x range, that works fine. Using yast, I set the host as so:

arrakis:~ # 
arrakis:~ # uname -a
Linux arrakis 3.11.10-25-default #1 SMP Wed Dec 17 17:57:03 UTC 2014 (8210f77) x86_64 x86_64 x86_64 GNU/Linux
arrakis:~ # 
arrakis:~ # hostname -f
arrakis:~ # 
arrakis:~ # hostname
arrakis:~ # 
arrakis:~ # cat /etc/hosts
# hosts         This file describes a number of hostname-to-address
#               mappings for the TCP/IP subsystem.  It is mostly
#               used at boot time, when no name servers are running.
#               On small systems, this file can be used instead of a
#               "named" name server.
# Syntax:
# IP-Address  Full-Qualified-Hostname  Short-Hostname
#       localhost

# special IPv6 addresses
::1             localhost ipv6-localhost ipv6-loopback

fe00::0         ipv6-localnet

ff00::0         ipv6-mcastprefix
ff02::1         ipv6-allnodes
ff02::2         ipv6-allrouters
ff02::3         ipv6-allhosts arrakis
arrakis:~ # 

that works fine. In yast, it looks like so:

YaST2 - lan @ arrakis

  Network Settings                                                                               
  ┌Global Options──Overview──Hostname/DNS──Routing─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐ 
  │┌Hostname and Domain Name──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐│ 
  ││Hostname                                                                            Domain Name                                                                           ││ 
  ││ ] Change Hostname via DHCP                                                                                                                                              ││ 
  ││[x] Assign Hostname to Loopback IP                                                                                                                                        ││ 
  │Modify DNS configuration Custom Policy Rule                                                                                                                                 │ 
  │Use Default Policy▒▒▒▒▒↓ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒↓                                                                                                                                 │ 
  │┌Name Servers and Domain Search List───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐│ 
  ││Name Server 1                                                                        ┌Domain Search─────────────────────────────────────────────────────────────────────┐ ││ 
  ││▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ │                                                                        │ ││ 
  ││Name Server 2                                                                        │                                                                                  │ ││ 
  ││▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ │                                                                                  │ ││ 
  ││Name Server 3                                                                        │                                                                                  │ ││ 
  ││▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ └──────────────────────────────────────────────────────────────────────────────────┘ ││ 
  │                                                                                                                                                                            │ 
  │                                                                                                                                                                            │ 

The question is, how do I assign a static ip address from yast itself?

Can you please at least tell which version of openSUSE you use?

Using YaST > System > Network devices you can set that you do not use DHCP, but traditional (with either ifup or wicked). Then you can set the IP address (and netmask and other parameters you need) in the tabs there.

I had some issue setting up static Ip on opensuse via yast. The problem was that after adding the connection and clicking save button settings used to just vanish. I used a trick. I connected the PC ethernet to a router giving DHCP. Now i could see the connection in YAST . I edited the settings and configured the static IP i needed and saved. I removed the ethernet cable and connected it to my static IP network and this time the settings did not vanish.
Hope this is helpful to people who had similar problem like mine.