PA-5250-AC Policy Rule, Service: Application-default for DNS Application

[IMTechSupport]

I have my PA-5250-AC with below sample rule. As per checking the traffic logs, I found out that UDP 53 is hitting rule 2 while TCP 53 is hitting rule 1. what is the possible cause?

No.	Source	Destination	Application	Service
1	A	B	… dns …	Application-default
2	A	B	Any	Any

made some research and found this article that says DNS, application default only matches TCP 53 but as checked with Applipedia
standard ports is tcp 53, udp 53, 5353.

https://docs.paloaltonetworks.com/pan-os/9-0/pan-os-admin/policy/security-policy/components-of-a-sec...

[kiwi]

Hi @IMTechSupport ,

When checking the logs, is the application actually being identified as DNS ?

Cheers,

-Kiwi.

[OtakarKlier]

Hello,

When it comes to external DNS, only your internal servers should be communicating with the secure dns providers you specify. This way you cant have data exfiltration over port 53 to some external source.

Regards,