Specifications

VLAN Support on Enterasys Switches
March 15, 2011 Page 6 of 20
Figure 2 Inside the Switch
AssumeaunicastuntaggedframeisreceivedonPort3intheexampleinFigure 2.Theframeis
classifiedforVLANC(theframe’sPVIDisVLANC).Theswitchwouldmakeitsforwarding
decisionbycomparingthedestinationMACaddresstoinformationpreviouslylearnedand
enteredintoitsfiltering
database.Inthiscase,theMACaddressislookedupintheFDBforFID3,
whichisassociatedwithVLANsCand D.Let’ssaytheswitchrecognizesthedestinationMACof
theframeasbeinglocatedoutPort4.
Havingmadetheforwardingdecisionbasedonentriesin
theFID,theswitchnowexaminesthe
portVLANegresslistofPort4todetermineifitisallowedtotransmitframesbelongingtoVLAN
C.Ifso,theframeistransmittedoutPort4.IfPort4hasnotbeenconfiguredtotransmitframes
belongingtoVLANC,the
frameisdiscarded.
If,ontheotherhand,aunicastuntaggedframeisreceivedonPort5,itwouldbeclassifiedfor
VLANE.Port5hasisownfilteringdatabaseandisnotawareof whataddressinginformationhas
beenlearnedbyotherVLANs.Port5looksupthe
destinationMACaddressinitsFID.Ifitfindsa
match,itforwardstheframeouttheappropriateport,ifandonlyif,thatportisallowedto
transmitframesforVLANE.Ifamatchisnotfound,theframeisfloodedoutallportsthatare
allowedtotransmit
VLANEframes.
VLAN Support on Enterasys Switches
Dependingontheproductfamily,Enterasy sswitchessupportamaximumofupto4094active
VLANs.Thereisadistinction,however,betweenthemaximumnumberofactiveVLANssome
switchessupportandtherangeofVLANID(VID)values.Forexample,whilethestackableand
standaloneswitchproductssupport1024active
VLANs,theydosupportVIDsfromanywherein
thefull802.1Qspecifiedrange.Thesedifferencesarelistedbelow.
Maximum Active VLANs
ThetotalnumberofactiveVLANssupportedonEnterasysswitchproductfamiliesis:
• Upto4094 onN‐Series,S‐Series,K‐Series,andX‐Series
• Upto1024 onstackable(A‐Series,B‐Series,C‐Series)andstandalone(D‐Series,G‐Series,I‐
Series)switchdevices
Configurable Range
Theallowableuser‐configurablerangeforVLANIDs(VIDs)is:
•From2through4094onN‐Series,S‐Series,K‐Series,andX‐Seriesswitches
Port 4
D
FID 3
Port 3
C
FID 3
Port 6
Port 2
B
FID 2
Port 1
A
FID 2
Default
FID 1
Port 5
E
FID 4