PFSense - Firewall - Debugging firewall rules

Change the System Log Settings

Navigate to Status → System logs → Settings.

Forward/Reverse Display: Checked.
Log firewall default blocks: Not Checked.
GUI Log Entries: 500. Increase to Number of log entries to show from default of 50.

NOTE: This should make it easier to ascertain the logs you want to monitor.

Navigate to Status → System logs → Firewall.

In Normal View:

NOTE: You need to refresh if you expect a rule was triggered by some action.

In Dynamic View:

NOTE: Here, you do not have to hit refresh.

Navigate to Firewall → Rules.

Under the interface(s) you want to debug:

Create a default deny rule at the end of the rule list.
Select Log packets that are handled by this rule.
Give the rule a very unique name. For other rules you want to debug: * Choose Log packets that are handled by this rule. * Give the rule a very unique name. Check the logs at Status → System logs → Firewall → Dynamic View**.

Tweak the firewall rules until you see the result you desire.

Click on the red/green blocked/accepted icons.

Will show a pop-up for the rule triggered, showing the unique name you gave to the rule.