'Enterasys SecureStack must be in \'router\' mode to have enable.
This message is generated \'% Invalid input detected at \'^\' marker.\' if enable is
not supported.'

def enable(self, cmd=u'enable', pattern=u'password', re_flags=re.IGNORECASE):

    output = u''
    if (not self.check_enable_mode()):
        self.write_channel(self.normalize_cmd(cmd))
        output += self.read_until_prompt_or_pattern(pattern=pattern, re_flags=re_flags)
        if (u'%    Invalid    input    detected    at' in output):
            return output
        self.write_channel(self.normalize_cmd(self.secret))
        output += self.read_until_prompt()
        if (not self.check_enable_mode()):
            raise ValueError(u'Failed    to    enter    enable    mode.')
    return output
