If you make a mistake (incorrect ip) while trying to ping.
For 1.3/1.4 you get such error:
[email protected]:~$ ping 100.64..1 Traceback (most recent call last): File "/usr/lib/python3.7/encodings/idna.py", line 165, in encode raise UnicodeError("label empty or too long") UnicodeError: label empty or too long The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/usr/libexec/vyos/op_mode/ping.py", line 222, in <module> ip = socket.gethostbyname(host) UnicodeError: encoding with 'idna' codec failed (UnicodeError: label empty or too long) [email protected]:~$
How it looks like in the crux:
vyos@r12-lts:~$ ping 100.64..1 ping: Unknown host: 100.64..1 vyos@r12-lts:~$