What do WRED drops and Policing drop on qos mean?

L4 Transporter

What do WRED drops and Policing drop on qos mean?


I have made qos configuration.

I have questions when am checking qos.

Look at the following command

show qos interface ethernet1/1 hw-counter

qid   name                 pass bytes       WRED drop   policing drop


0     default              3408809811               0               0

-2    bypass              14803984933          584640               0

I don't know what WRED drop and policing drop mean and what two counters are difference.

Tags (1)
L5 Sessionator



Congestion Management

When a queue is filling faster than it can be emptied, the device has two choices as to where to drop traffic. It can wait until the queue is full and simply drop packets as they arrive (tail dropping), or it can detect incipient congestion and proactively begin to drop packets based on probability function that is tied to average depth of the queue. This technique is called random early drop (RED). PAN-OS uses weighted RED (WRED) algorithm.


Policing and Shaping

Policing is performed to avoid unintentional starvation of the QoS priority queues. Policers mark packets that go above the burst rate as out of conformance, which alerts the scheduler to allow the packets to be forwarded only if the interface is not experiencing congestion. When the interface is experiencing congestion, out of conformance packets are either automatically discarded or reclassified.

Not all Palo Alto Networks firewalls support policing, refer to the following table:

Platform Policing


Not Supported


Not Supported

PA-2000 Series

Not Supported

PA-4000 Series

Supported (on egress interface)

PA-5000 Series

Supported (on egress interface)


Also following doc has the same information on page 5.


Hope this helps.

Thank you


L4 Transporter


Thanks for the answer.

If I don't make QoS configuration, FW will be performed tail dropping on congestion management.

And if I make QoS Configuration, FW will be performed WRED on congestion management.


L3 Networker

I don't know exact this function still

It is hard to understand

Will you plz let me know to show what it is?

Like what you see?

Show your appreciation!

Click Like if a post is helpful to you or if you just want to show your support.

Click Accept as Solution to acknowledge that the answer to your question has been provided.

The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!

These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!

The LIVEcommunity thanks you for your participation!