PyEZ デバイス接続は ConnectRefusedError を返します。
>>> dev = Device(host='xx.xxx.xx.xx', user='xxxx',password='xxxx')
>>> dev.open()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python27\lib\site-packages\jnpr\junos\device.py", line 459, in open
raise EzErrors.ConnectRefusedError(self)
jnpr.junos.exception.ConnectRefusedError: ConnectRefusedError(xx.xxx.xx.xx)