What is the format for specifying multiple IP addresses (is it comma separated?). It would be good to put that format in this comment. I'd also mention that these are CIDR ranges and not individual addresses.

```
  parser.add_option("--ips-allowed", default="0.0.0.0/0",
      help="CIDR IP ranges allowed to access the machine. Multiple ranges can be separated with commas.")
```