This server has 04 (four) network adapters but take in mind that, 02 (two) of them are FoD (Feature on Demand) and you may need additional license to use these one... and the another one if configured to "Dedicated", can be used only by IMM (management).
To use the network interface dedicated for the IMM, change the IMM network interface configuration for "Shared".
Here is some more about: IBM System x