what a nice monologue
Ok, i sorted it out. It was a local problem on my notebook because of a damn virtual VMWare (Fusion) vmnet1 iface which occupied 192.168.170.1 which in turn lead to a routing table locally who send all requests to 192.168.170.x to the VMware interface.
I looked at the wrong place the last thousand hours grrrr. Now i reconfigured VMware so that vmnet1 sits on a different IP.
Marc