Enterasys Enterasys SecureStack B2 B2G124-24 Specifiche Pagina 391

  • Scaricare
  • Aggiungi ai miei manuali
  • Stampa
  • Pagina
    / 600
  • Indice
  • SEGNALIBRI
  • Valutato. / 5. Basato su recensioni clienti
Vedere la pagina 390
SecureStack B2 Configuration Guide 14-1
14
IGMP Configuration
ThischapterdescribestheIGMPConfigurationsetofcommandsandhowtousethem.
IGMP Overview
About IP Multicast Group Management
TheInternetGroupManagementProtocol(IGMP)runsbetweenhostsandtheirimmediately
neighboringmulticastdevice.Theprotocol’smechanismsallowahosttoinformitslocaldevice
thatitwantstoreceivetransmissionsaddressedtoaspecificmulticastgroup.
Amulticastenableddevicecanperiodicallyaskitshostsiftheywantto
receivemulticasttraffic.If
thereismorethanonedeviceontheLANperformingIPmulticasting,oneofthesedevicesis
elected“querierandassumestheresponsibilityofqueryingtheLANforgroupmembers.
BasedonthegroupmembershipinformationlearnedfromIGMP,adevicecandeterminewhich(if
any)multicast
trafficneedstobeforwardedtoeachofitsports.AtLayer3,multicastdevicesuse
thisinformation,alongwithamulticastroutingprotocol,tosupportIPmulticastingacrossanIP
network.
IGMPprovidesthefinalstepinanIPmulticastpacketdeliveryservice,sinceitisonlyconcerned
withforwarding
multicasttrafficfromthelocaldevicetogroupmembersonadirectlyattached
subnetworkorLANsegment.
ThisdevicesupportsIPmulticastgroupmanagementbypassivelysnoopingontheIGMPquery
andIGMPreportpacketstransferredbetweenIPmulticastdevicesandIPmulticasthostgroupsto
learnIPmulticastgrou pmembers.
The
purposeofIPmulticastgroupmanagementistooptimizeaswitchednetwork’sperformance
somulticastpacketswillonlybeforwardedtothoseportscontainingmulticastgrouphostsor
multicastdevicesinsteadoffloodingtoallportsinthesubnet(VLAN).
About Multicasting
Multicastingisusedtosupportrealtimeapplicationssuchasvideoconferencesorstreaming
audio.Amulticastserverdoesnothavetoestablishaseparateconnectionwitheachclient.It
merelybroadcastsitsservicetothenetwork,andanyhoststhatwanttoreceivethemulticast
registerwiththeirlocalmulticast
switch/router.Althoughthisapproachreducesthenetwork
overheadrequiredbyamulticastserver,thebroadcasttrafficmustbecarefullyprunedatevery
For information about... Refer to page...
IGMP Overview 14-1
Configuring IGMP at Layer 2 14-2
Vedere la pagina 390
1 2 ... 386 387 388 389 390 391 392 393 394 395 396 ... 599 600

Commenti su questo manuale

Nessun commento