# drop-probability

## QFX5100, EX4600, QFX3500, and QFX3600, Switches, QFabric Systems

drop-probability 0 drop-probabilityhigh-value;

## QFX10000 Switches

drop-probabilitypercentage1percentage2...percentage32;

## Hierarchy Level

[edit class-of-service drop-profilesprofile-nameinterpolate]

## Description

When configuring WRED, map the packet `drop-probability`

to the fullness of a queue (fill-level). You configure the `fill-level`

and `drop-probability`

statements in related pairs. The pairs of fill level and drop probability
values set a probability of dropping packets at a specified queue
fullness value.

On switches that support only two fill level/drop probability pairs, the first drop probability is always zero. The first fill level/drop probability pair sets the drop start point, and the second fill level/drop probability pair sets the drop end point.

On switches that support 32 fill level/drop probability pairs, the first fill level/drop probability pair sets the drop start point, and the last fill level/drop probability pair sets the drop end point.

As the queue fills from the drop start point to the drop end point, the rate of packet drop increases in a curve pattern. The higher the queue fill level, the higher the probability of dropping packets.

## Options

0 (switches that support only two fill level/drop
probability pairs)—Probability that packets will drop at the
lowest `fill-level`

value. This is always zero, because until
the queue reaches the specified low `fill-level`

value, no
packets are scheduled to drop.

**Range:**0

`high-value` (switches that support
only two fill level/drop probability pairs)—The maximum probability
that packets will drop before queue fullness exceeds the high value
of the queue `fill-level`

, expressed as a percentage. If
the queue fills beyond the high `fill-level`

value, all packets
drop.

**Range:**0 through 100 percent

`percentage1 percentage2 ... percentage32` (switches that
support 32 fill level/drop probability pairs)—The probability
that packets will drop before the queue fullness exceeds the `fill-level`

value, expressed as a percentage. Each drop probability
pairs with a queue fill level to define the probability of a packet
dropping at a specified queue fullness.

**Range:**0 through 100 percent

## Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.## Release Information

Statement introduced in Junos OS Release 11.1.