Nace now requires the Parallel::Forkmanager module. Serial scans are
just not feasable on a large network.

Where $NAGIOS is the root of your nagios directory tree and $SRC is
the root of this tarball:

mkdir -p $NAGIOS/scripts/{bin,lib}
cp $SRC/scripts/* $NAGIOS/scripts/bin
cp $SRC/lib/* $NAGIOS/scripts/lib

Also, add the following to your .profile (.bash_profile, .bashrc, etc...)

export PERLLIB="$NAGIOS/scripts/lib:$PERLLIB"

Lastly, the example uses $NAGIOS/Auto to contain automatically created
configurations. This is optional.

