Update: it does work, if i change the Tunnel Interface Number from 0 to 10

we already did

sw(config)#int tunnel 0 sw(config-if)#ip address x.x.x.x y.y.y.y

Hi Markin #interface tunnel 0 I am not able to set #ip address 10.0.0.1 255.255.255.252if i issue switch(config-if)#ip ? i only get a very short list of arguments:(config-if)#ip ? Interface IP configuration subcommands: access-group Specify ...

With version 17.15.05, we cannot configure an IP address for a GRE tunnel interface. This was still possible with version 17.05.03.