pfSense

#1979 added a System Aliases facility users can utilize to make rules with the built-in system aliases, and it would be nice to add some pre-defined lists of reserved networks to that.

Examples to start with could be:

• IPv4 Private Addresses: 192.168.0.0/16, 10.0.0.0/8, 172.16.0.0/12
• IPv6 Private Addresses: fc00::/7

• IPv6 Link Local: fe80::/10

• IPv4 Multicast: 224.0.0.0/4
• IPv6 Multicast: ff00::0/8

• Localhost: 127.0.0.1, ::1

The IPv4 and IPv6 aliases could likely be combined.

Tricky part might be finding names which do not or cannot conflict with existing user-defined aliases, or renaming conflicting user aliases.