Enterasys D-Series CLI Reference 12-1
12
Port Priority and Rate Limiting Configuration
ThischapterdescribesthePortPriorityandRateLimitingsetofcommandsandhowtousethem.

Port Priority Configuration Summary

TheDSeriesdevicesupportsClassofService(CoS),whichallowsyoutoassignmissioncritical
datatohigherprioritythroughthedevicebydelayinglesscriticaltrafficduringperiodsof
congestion.Thehigherprioritytrafficthroughthedeviceisservicedfirstbeforelowerpriority
traffic.TheClassofServicecapabilityofthedeviceisimplementedbyapriorityqueueing
mechanism.ClassofServiceisbasedontheIEEE802.1D(802.1p)standardspecification,and
allowsyoutodefineeightpriorities(0 through 7)andassignthemtotransmitqueuesforeach
port.
Apriority0through7canbesetoneachport,with0beingthelowestpriority.Aportreceivinga
framewithoutpriorityinformationinitstagheaderisassignedapriorityaccordingtothedefault
prioritysettingontheport.Forexample,ifthepriorityofaportissetto4,theframesreceived
throughthatportwithoutapriorityindicatedintheirtagheaderareclassifiedasapriority4and
transmittedaccordingtothatpriority.Inaddition,thedevice’sratelimitingcapabilitiesallowyou
tofurtherprioritizetrafficbylimitingtherateofinboundtrafficonaperport/prioritybasis.

Configuring Port Priority

Purpose
Tovieworconfigureportprioritycharacteristicsasfollows:
•DisplayorchangetheportdefaultClassofService(CoS)transmitpriority(0through7)of
eachportforframesthatarereceived(ingress)withoutpriorityinformationintheirtag
header.
For information about... Refer to page...
Port Priority Configuration Summary 12-1
Configuring Port Priority 12-1
Configuring Priority to Transmit Queue Mapping 12-4
Configuring Quality of Service (QoS) 12-6
Configuring Port Traffic Rate Limiting 12-10
Note: When CoS override is enabled using the set policy profile command as described in “set
policy profile” on page11-3, CoS-based classification rules will take precedence over priority
settings configured with the set port priority command described in this section.