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Example: Configuring RED Drop Profiles
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.
Drop Profile |
Drop Probability |
Queue Fill Level |
|---|---|---|
|
Between 0 (never dropped) and 100 percent (always dropped) |
Between 95 and 100 percent |
|
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.
[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:
Configure the lower drop probability for normal, non-PLP traffic.
[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
Configure a queue fill level for the lower non-PLP drop probability.
[edit class-of-service drop-profiles af-normal interpolate] user@host# set fill-level 95 user@host# set fill-level 100
Configure the higher drop probability for PLP traffic.
[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
Configure a queue fill level for the higher PLP drop probability.
[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.
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.