I am using MPICH 1.4.1p1 with ch3:sock device, and have noticed that it is vulnerable to being scanned by nmap. With a rank sitting on an MPI_Recv, if you use nmap to scan the rank's listen ports with a command like: nmap -p <port> -T4 -A -v <host> MPI_Recv with detect an error and exit. Has this been fixed in newer versions of MPICH?