URL Filtering Order
122198
Created On 09/26/18 13:50 PM - Last Modified 06/15/23 21:55 PM
Symptom
What happens when a URL matches multiple patterns (multiple custom URL filtering categories and allow/block-list) within a URL filtering profile?
Environment
- Palo Alto Firewall.
- Any PAN-OS.
- URL Filtering.
Resolution
When a URL matches multiple categories, the category chosen is the one that has the most severe action defined below (block being most severe and allow least severe).
- block
- override
- continue
- alert
- allow
For example, if *.yahoo.com exists in MyAlertList and MyBlockList simultaneously) within the same URL filtering profile and www.yahoo.com is the URL, the action will be “block” and the category name will be “MyBlockList”. This is similar to the original behavior between “allow-list” and “block-list” in that the block-list will be checked BEFORE the allow-list if a URL matches both “allow-list” and “block-list”.
The priority for URL filtering is:
- block list
- allow list
- custom categories
- cached
- pre-defined categories