If you didn't configure DNS forwarding and try to show statistics, this will result in an error.
[email protected]:~$ show dns forwarding statistics Traceback (most recent call last): File "/usr/libexec/vyos/op_mode/dns_forwarding_statistics.py", line 7, in <module> from vyos.config import cmd ImportError: cannot import name 'cmd' from 'vyos.config' (/usr/lib/python3/dist-packages/vyos/config.py) [email protected]:~$