Zte ZXR10 5900E Series - Page 140

ZXR105900ESeriesCongurationGuide(IPv4Routing)
ParameterDescription
<peer-group-name>Nameofthepeergroup
ConguringBGPRouteAdvertisement
lBGPRouteAdvertisementRules
TheroutestobeadvertisedbyBGPhavetoexistinIGProutingtablealready.The
sourceofBGProuteupdatingisthatinjectIGProutinginformationtoBGP .Ithas
aninuenceonthestabilityofInternetroutesdirectly.Therearetworouteinjection
methods,dynamicinjectionandstaticinjection.
Dynamicinjectionisdividedintotwotypes,fulldynamicinjectionandselective
dynamicinjection.
FulldynamicinjectionmeansthatallIGProutesareredistributed(Redistribution)to
BGP .Thismethodisveryeasytocongurebutcontrollabilityisweakandlowefcient.
SelectivedynamicinjectionmeansthatinjectapartofIGProutestoBGP(use
networkcommand).Thismethodveriesaddressandmaskrst,whichimproves
controllabilityandefciency.Inthisway,theerrorroutinginformationcanbeavoided
toinject.
However,nomatterwhichmethodisadopted,therouteswillbeunstable.That
becausedynamicinjectiontotallydependsonIGPinformation.Whenrouteapping
occursonIGProutes,BGProuteupdatewillbeaffected.Lotsofupdatingpackets
aregeneratedbecauseoftheunstableroutes,andthebandwidthwillbewasted
heavily.T omakeupthisdisadvantage,routedampeningandaggregationcanbe
adoptedontheborder.
Staticinjectionsolvestheunstableroutesgreatly.ItinjectsstaticroutestoBGP .
Staticroutesareaddedmanually,soitisinuencedbyIGProuteapping.Therefore,
therepeatedupdatingwillbepreventedbythestability.However,ifthesubnetwork
partitionisnotveryclear,staticinjectionalsobringsdataowblocking.
Inconclusion,therearethreeBGProuteadvertisementmethods.
àUsenetworkcommandtoadvertiseroutes.
àUseredistributecommandtoredistributetherouteslearnedbyotherprotocols
toBGP .
àUseBGProuteaggregationtoadvertisement.
lAdvertisingRoutesbynetworkCommand
TheroutestobeadvertisedbyBGPhavetoexistinIGProutingtablealready.
ThecommonmethodofBGProuteadvertisementistoselectthenetworksegmentto
advertisebythenetworkcommand.Thiscommandspeciesthedestinationnetwork
segmentandmask,andthentherouteswhichmatchwiththeruleaccuratelywillenter
intoBGProutingtable.Therouteswillbelteredandadvertised.
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SJ-20150114102049-003|2015-01-15(R1.0)ZTEProprietaryandCondential