I have latest version of FF8 and cluster with IB. I use iMPI(32-bit) version to run the program. There is no ethX interface from ifconfig output but ib0 is present. Do we really need to use 32-bit "provider"'s library for IB? Or, in another words, how do i know, FF uses IB interface (or it doesn't)? I added $p2p net=... mask=... bind=.t. $end line to my input file (net is IP for IB interface) plus additional keywords from the manual. Does it help in such situation? Any comments or suggestions would be great. I should also mention, i don't have any problem to run FF. It works fine on more then 1 nodes.