Support User Manuals

Enterasys Networks XSR CLI Router User Manual

Open as PDF

of 684

Policy-Map Commands

12-92 Configuring Quality of Service

XSR(config)#policy-map policy75

XSR(config-pmap<policy75>)#class acl203

XSR(config-pmap-c<acl203>)#bandwidth percent 35

XSR(config-pmap-c<acl203>)#queue-limit 50

random-detect (RED)

ThiscommandconfiguresREDforapolicymap.

ThiscommandconfiguresandenablesRandomEarlyDetect(RED)fortheclass.REDisa

congestionavoidancemechanismthatslowstrafficbyrandomlydroppingpackets during

congestionandisusefulwithprotocolslikeTCPthatrespondtodroppedpacketsbyreducingthe

transmission

rate.WhileREDmaybeimplementedusingWRED,thiscommandisretainedfor

compatibilitywithearlierreleasesandsimplicityofconfigurationwhenonlyREDisrequired.

Syntax

random-detect min-thres max-thres [mark-prob]

Syntax of the “no” Form

ThenoformofthiscommanddisableREDonaninterface:

no random-detect

Mode

Policy‐MapClassconfiguration:XSR(config-pmap-c-<xx>)#

Defaults

• Disabled

•Mark‐prob:10

Example

ThefollowingexampleenablesRED.Theminimumandmaximumthresholdsare24and40,

respectively.Thedroppingprobabilityis1/4.

XSR(config)#policy-map foobar

XSR(config-pmap<foobar>)#class alpha

XSR(config-pmap-c<alpha>)#random-detect 24 40 4

min-thres

Peaklimitofaveragepacketqueuelength,rangingfrom1to4096,beyond

whichtheXSRrandomlydropspackets.

max-thres

Peaklimitofaveragepacketqueuelength,rangingfrom1to4096,beyond

whichallpacketsaredropped.

mark-prob

Markprobabilitydenominator,rangingfrom1to65,536.Thisistheliklihood

ofqueuedpacketsbeingdroppedwhentheirnumberexceedingthe

minimumthresholdisbetween0and(1/mark‐prob).Whenthepeakthreshold

isreached,dropprobabilityis1dividedbythepeakprobability.

previous next