#For Gigabit Interconnect try this:
./configure   --enable-mpi=yes    --with-mpi-prefix=/opt/mpich2/intel/14.0/

Remark:
To make executables "universal" i.e.  to be used both on Intel Xeon and AMD Opterons CPUs (nodes, computers),
use the following additional option in configuration procedure: 

"--enable-optim=safe"

So, for Gigabit connection configuration line will look like:

./configure   --enable-mpi=yes  --enable-optim=safe    --with-mpi-prefix=/opt/mpich2/intel/14.0/