Zte ZXR10 5900E Series - Figure 4-4 Neighbor Establishment on a Broadcast Network; Figure 4-5 DIS on a Broadcast Network

ZXR105900ESeriesCongurationGuide(IPv4Routing)
Figure4-4NeighborEstablishmentonaBroadcastNetwork
lDISelectiononabroadcastlink
TheIS-ISprotocolselectsaspeciedDesignateIS(DIS)toreducetheneighbor
informationcarriedintheLSPsentonthebroadcastnetworkandsimplifythenetwork
architecture.TheIS-ISprotocolconsidersthenetworkasaDISorapseudo-node.
Eachintermediatesystem,includingtheDISadvertiseslinkstothepseudo-node.The
DISalsoadvertisesalinktoallintermediatesystemsthatareconnectedwithitself,
seeFigure4-5.
Figure4-5DISonaBroadcastNetwork
ADISisthesystemthathasthehighestpriorityonabroadcastnetwork.Ifthepriorities
ofallintermediatesystemsarethesame,theintermediatesystemwiththegreatest
MACaddressistheDIS.Generally,eachnetworkhastwoDISs:theL1DISandthe
L2DIS.
TheconditionsforelectingaDISareasfollows:
àWhentheIS-ISprocessisstartedonarouter,theDISelectionisperformedafter
threeHellopacketsaresent
4-6
SJ-20150114102049-003|2015-01-15(R1.0)ZTEProprietaryandCondential