Folks, i noticed mpirun (trunk) hangs when running any mpi program on two nodes *and* each node has a private network with the same ip (in my case, each node has a private network to a MIC)
in order to reproduce the problem, you can simply run (as root) on the two compute nodes brctl addbr br0 ifconfig br0 192.168.255.1 netmask 255.255.255.0 mpirun will hang a workaroung is to add --mca btl_tcp_if_include eth0 v1.8 does not hang in this case Cheers, Gilles