pfSense

The IPv6 addresses there are displayed using the [1:2::3]:80 format with [IPv6-address]:port which is good for display. But the code seems to be trying to resolve the IPv6 address with the square brackets around it.

I don't have IPv6 resolution where I am right now, so can;t really test. But the change in this pull request at least makes it now come back with "Cannot resolve" on the GUI, where previously it just appeared to do nothing.
https://github.com/pfsense/pfsense/pull/3047

Can you test and confirm if it works or not?

Note: Once a fix is confirmed for this, the same issue needs to be checked in other places where IPv6 reverse lookups are done.

It works!
Now for ipv6 addresses ptr records are returned,
and in case of no prt "Cannot resolve".
Great work, thanks!

Thanks for testing.
The Firewall Log Dynamic view does not have the reverse lookup buton, so it won't be broken!
The dashboard Firewall Log widget works a bit differently for reverse lookups, taking the user to the Diagnostics DNS Lookup page and filling in the address. That is doing the right thing with an IPv6 address - no square brackets around it.
So I think this place in status_logs_filter.php is the only place to fix.

This issue could be changed from "feature" to "bug".