Temporarily open the ICMP firewall. Tricks Windows into allowing
    ICMP packets for a short period of time (~ 1 minute)

def open_icmp_firewall(host):
    """Temporarily open the ICMP firewall. Tricks Windows into allowing
    ICMP packets for a short period of time (~ 1 minute)"""
    # We call ping with a timeout of 1ms: will return instantly
    with open(os.devnull, 'wb') as DEVNULL:
        return subprocess.Popen("ping -4 -w 1 -n 1 %s" % host,
                                shell=True,
                                stdout=DEVNULL,
                                stderr=DEVNULL).wait()