Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Example: Configuring RED Drop Profiles

This example shows how to configure RED drop profiles.


Before you begin, determine which type of profile you want to configure. See Example: Configuring Segmented and Interpolated Style Profiles.


A drop profile is a feature of the RED process that allows packets to be dropped before queues are full. Drop profiles are composed of two main values the queue fullness and the drop probability.

You can control congestion by configuring RED drop profiles, if the device supports assured forwarding. RED drop profiles use drop probabilities for different levels of buffer fullness to determine which scheduling queue on the device is likely to drop assured forwarding packets under congested conditions. The device can drop packets when the queue buffer becomes filled to the configured percentage. Assured forwarding traffic with the PLP bit set is more likely to be discarded than traffic without the PLP bit set.

In this example, you configure a drop probability and a queue fill level for both PLP and non-PLP assured forwarding traffic.

Table 1 shows how to configure the RED drop profiles listed.

Table 1: Sample RED Drop Profiles

Drop Profile

Drop Probability

Queue Fill Level

af-normal—For non-PLP (normal) assured forwarding traffic

Between 0 (never dropped) and 100 percent (always dropped)

Between 95 and 100 percent

af-with-plp—For PLP (aggressive packet dropping) assured forwarding traffic

Between 95 and 100 percent (always dropped)

Between 80 and 95 percent



CLI Quick Configuration

To quickly configure RED drop profiles, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode.

To configure RED drop profiles:

  1. Configure the lower drop probability for normal, non-PLP traffic.

  2. Configure a queue fill level for the lower non-PLP drop probability.

  3. Configure the higher drop probability for PLP traffic.

  4. Configure a queue fill level for the higher PLP drop probability.


From configuration mode, confirm your configuration by entering the show class-of-service command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.


Verifying RED Drop Profiles Configuration


Verify that the RED drop profiles are configured properly.


From operational mode, enter the show class-of-service command.