Hallo Markus,
das ist leider so, wie Du bereits bemerkt hast --> not supported !!!

http://www-1.ibm.com/support/docview...05b55ae&rs=110

Note the following restrictions:

o The 1000 Mbps speed is not supported in Half Duplex (HDX) mode.
o Systems Network Architecture (SNA) is not supported.
o A cross-over cable is not supported.