Figure 1: Using the Perl ping.pm module to check the availability of the Alias IP

sub PingHost{
    # Subroutine for checking the availablity of a passed host.
    # Returns true if host is alive or false if dead.
    #
    # NOTE: Specifying the ``icmp'' protocol requires that the program
    # be run as root or that the program be setuid to root.
    local($host)=@_;

    $p = Net::Ping->new("icmp");
    if ($p->ping($host,$PING_COUNT)){
            return true;
    }else{
            return false;
    }
    undef($p);
}