Linux networking: A tragedy in three acts

ACT 1:
Wherein the system administrator writes their /etc/network/interfaces file as is the custom.

ACT 2:
Wherein the kafkaesque outputs of basic networking commands threaten basic sanity. Behold:

```
# ifup ens3:1
RTNETLINK answers: File exists
Failed to bring up ens3:1.
# ifdown ens3:1
ifdown: interface ens3:1 not configured
```

ACT 3:
Wherein all sanity is lost:

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