Thanks for the hint, but no. It seems to be more complicated. We do have multiple network segments. The printer works well, with static or DHCP setup inside the 1st and 2nd, however, in the third, the one inside which he should finally be, he is not accessible at all. DHCP is not turned on in that third segment, only static addresses are allowed. This is where all other printers we use in our office are placed, and all but the M602 are working.
For example, I can change the M602 it's static IP address for 1st or 2nd segment, plug the network cable to one of them and it works, set the IP to another address out of the range of the 3rd, plug the network cable into 3rd segment, not accessible at all.