pfSense

via Brian Candler on mailing list.

When creating a network alias which contains an IPv6 address, some additional data validation is required. Specifically, it lets you enter the following:

Firewall > Aliases > [+]
Name: foo
Type: Network(s)
Network(s): [+]
[fc00:123::/48 ] [ /48 ]

This happened to me for real when copy-pasting a subnet into the first field.

The data is accepted, and the alias then has value "fc00:123::/48/48". However, this prevents the ruleset from loading. More seriously, the entire ruleset is left empty. That is: after clicking Apply, 'pfctl -sr' shows nothing at all, and the firewall is open.

If you then navigate to another page, you do see an error notification:

"
02-10-14 17:11:31 [ There were error(s) loading the rules: /tmp/rules.debug:26: syntax error - The line in question reads [26]: table { fc00:123::/48/48 } ]