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{ "lLangCode": "en", "lName": "English", "lCountryCode": "us", "transcode": "en_US" }
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Example: Configuring RED Drop Profiles

date_range 13-Jan-21

This example shows how to configure RED drop profiles.

Requirements

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

Overview

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

Configuration

Procedure

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.

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[edit]
set class-of-service drop-profiles af-normal interpolate drop-probability 0
set class-of-service drop-profiles af-normal interpolate drop-probability 100 
set class-of-service drop-profiles af-normal interpolate fill-level 95 
set class-of-service drop-profiles af-normal interpolate fill-level 100 
set class-of-service drop-profiles af-with-PLP interpolate drop-probability 95 
set class-of-service drop-profiles af-with-PLP interpolate drop-probability 100 
set class-of-service drop-profiles af-with-PLP interpolate fill-level 80 
set class-of-service drop-profiles af-with-PLP interpolate fill-level 95 

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.

    content_copy zoom_out_map
    [edit]
    user@host# edit class-of-service
    user@host# edit drop-profiles af-normal interpolate
    user@host# set drop-probability 0
    user@host# set drop-probability 100
    
  2. Configure a queue fill level for the lower non-PLP drop probability.

    content_copy zoom_out_map
     [edit class-of-service drop-profiles af-normal interpolate]
    user@host# set fill-level 95
    user@host# set fill-level 100
    
  3. Configure the higher drop probability for PLP traffic.

    content_copy zoom_out_map
    [edit]
    user@host# edit class-of-service
    user@host# edit drop-profiles af-with-PLP interpolate
    user@host# set drop-probability 95
    user@host# set drop-probability 100
    
  4. Configure a queue fill level for the higher PLP drop probability.

    content_copy zoom_out_map
    [edit class-of-service drop-profiles af-with-PLP interpolate]
    user@host# set fill-level 80
    user@host# set fill-level 95
    

Results

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.

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user@host# show class-of-service
    drop-profiles {
    af-normal {
        interpolate {
            fill-level [ 95 100 ];
            drop-probability [ 0 100 ];
        }
    }
    af-with-PLP {
        interpolate {
            fill-level [ 80 95 ];
            drop-probability [ 95 100 ];
        }
    }
}

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

Verification

Verifying RED Drop Profiles Configuration

Purpose

Verify that the RED drop profiles are configured properly.

Action

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

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