Zte ZXR10 5900E Series - Figure 5-11 Restrict the Number of Route Advertisements Received by Neighbor

ZXR105900ESeriesCongurationGuide(IPv4Routing)
Figure5-11RestricttheNumberofRouteAdvertisementsReceivedbyNeighbor
CongurationonS1:
S1(config)#routerbgp100
S1(config-bgp)#neighbor10.1.1.1remote-as200
S1(config-bgp)#neighbor10.1.1.1maximum-prefix10drop-routes
CongurationonS2:
S2(config)#routerbgp200
S2(config-bgp)#neighbor10.1.1.2remote-as100
S2(config-bgp)#neighbor10.1.1.2maximum-prefix20restart1
Withoutthecongurationoftimeforwaitingreconnection(useparameterwarning-onl
y),whenS1advertisesmorethan20routestoS2,S2willdisplaythealarminformation
only.
CongurationonS2:
S2(config)#routerbgp200
S2(config-bgp)#neighbor10.1.1.2remote-as100
S2(config-bgp)#neighbor10.1.1.2maximum-prefix20warning-only
lFilteringRoutesbyUsingAS_PATH
AS-PATHisawell-knownmandatoryattribute.Theattributeisapathled,whichis
composedofaseriesofASnumberspassingbyaroutepointingtoonedestination.
WhentheoriginASinitiatesaroutetootherexternalBGPpeers,itwilladditsAS
numberintotheroute.Subsequently,eachroutereceiverwilladditsASnumberinto
routeandplaceASnumberontheheadofASsequencewhensendingtherouteto
otherBGPpeers.
BGPadoptsAS-PATHasthefactorofitsrouteupdatetorealizeno-looptopology
ofInternet.EachroutecontainsalistwithallpassedASnumbers.Whentheroute
isadvertisedtoitsoriginAS,ASexaminesitsASnumberhasbeenexistedinAS
sequence,anditwillnotacceptthisroute.Meanwhile,AS-PATHwillbeusedfor
decidingtheoptimumroute.Whenmultipleroutes(theirattributesexceptforAS-PATH
arethesame)tothesamedestinationareavailable,BGPwillselectaroutewith
theshortestpathastheoptimumrouteaccordingtoAS-PATH.Therefore,increasing
AS-PATHcanaffectBGProuteselection.
WhenallroutesofoneormultipleASrequireltering,theltermethodbasedon
AS-PATHisusuallyadopted.
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SJ-20150114102049-003|2015-01-15(R1.0)ZTEProprietaryandCondential