Random-Detect - Cisco ME 3800X Command Reference Manual

random-detect

random-detect
To configure WRED for a class in a policy map, use the random-detect command in policy-map class
configuration mode. To disable WRED, use the no form of this command.
Syntax Description
dscp-based
prec-based
cos-based
Command Default WRED is disabled by default.
Command Modes Policy-map class configuration when used in a policy map (config-pmap-c)
Command History Release
15.1(2)EY
Usage Guidelines Keywords
If you choose not to use either the dscp-based or the prec-based keywords, WRED uses the IP
Precedence value (the default method) to calculate the drop probability for the packet.
WRED Functionality
WRED is a congestion avoidance mechanism that slows traffic by randomly dropping packets when
congestion exists. WRED is most useful with protocols like Transport Control Protocol (TCP) that
respond to dropped packets by decreasing the transmission rate.
The router automatically determines parameters to use in the WRED calculations. To change these
parameters, use the random-detect precedence command.
WRED in a Policy Map
You can configure WRED as part of the policy map for a standard class or the default class. If you
configure WRED, its packet drop capability is used to manage the queue when packets exceeding the
configured maximum count are enqueued. If you configure the queue-limit command, tail drop is used.
To configure a policy map and create class policies, use the policy-map and class (policy-map)
commands.
Cisco ME 3800X and ME 3600X Switch Command Reference
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random-detect [dscp-based | prec-based|cos-based]
no random-detect
(Optional) Specifies that WRED is to use the differentiated services code
point (DSCP) value when it calculates the drop probability for a packet.
(Optional) Specifies that WRED is to use the IP Precedence value when it
calculates the drop probability for a packet.
(Optional)Specifies that WRED is to use the Specific IEEE 802.1Q CoS
values from 0 to 7
Modification
This command was introduced.
Chapter 2 Cisco ME 3800X and ME 3600X Switch Cisco IOS Commands
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