def kill_process(device, process="tcpdump"):
    """Kill any active process

    :param device: lan or wan
    :type device: Object
    :param process: process to kill, defaults to tcpdump
    :type process: String, Optional
    :return: Console ouput of sync sendline command after kill process
    :rtype: string
    """
    device.sudo_sendline("killall %s" % process)
    device.expect(device.prompt)
    device.sudo_sendline("sync")
    device.expect(device.prompt)
    return device.before