User manual

 16‐PortGigabitEthernetPoE+Web‐ManagedSwitchwith2SFPPorts
26
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6.4 VLAN
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AvirtualLAN(VLAN)isanybroadcastdomainthatispartitionedandisolatedinacomputernetworkatthedatalinklayer
(OSIlayer2).VLANsaredatalinklayer(OSIlayer2)constructs,analogoustoIPsubnets,whicharenetwork‐layer(OSI
layer3)constructs.VLANscanbeusedtopartitionalocalnetworkintoseveraldistinctivesegments. 
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VLANtechnologyprovidesthefollowingadvantages:
1. BroadcasttrafficdoesnotcrossintodifferentVLANs,whichreducesbandwidthutilizationandimproves
networkperformance.
2. SecurityinyourLANcanbeimproved,sincepacketsindifferentVLANscannotcommunicatewitheachother
directly. 
3. WithVLAN,clientscanbeallocatedtodifferentworkinggroups,andusersfromthesamegroupdonothaveto
bewithinthesamephysicalarea,whichmakesnetworkmaintenancemucheasierandmoreflexible. 
VLANtechnologyknowsthreetypesofports—access,trunkandhybridports.
1. AccessPorts(untagged)
a. AccessportsaredesignedtotaganyincomingpacketwiththeVLANIDtheporthasbeenassignedto.
b. TaggedVLANpacketsarrivingattheaccessportaredroppedbytheswitch.
c. AsfarastheIntellinetswitchisconcerned,anyportthatisn’tdefinedasatrunkorhybridportis
consideredanaccessport.
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2. TrunkPorts(tagged)
a. TrunkportsaredesignedtofilteroutpacketsthathaveeithernoVLANtagorVLANtagsthatarenot
ontheallowedVLANIDlist.
b. TrunkportsdonotremoveanyexistingVLANtagsfromincomingpackets.
c. TrunkportsdonotaddaVLANtagtoanyincominguntaggedpacket.
d. Trunkportsareidealforswitch‐to‐switchconnectionsorfordevicesthathavetheabilitytotagpackets
bythemselvessuchasVoIPphones.
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3. HybridPorts
a. Theseareacombinationofaccessandtrunkports. 
b. HybridportswilltaganyincomingpacketthathasnoVLANIDwiththeVLANIDtheporthasbeen
assignedto.
c. HybridportswillalsoactastrunkportsforpacketsthathaveaVLANtag.
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