Enterasys G3G170-24 - Split-Horizon Poison

split-horizon poison
Enterasys G-Series CLI Reference 16-7
Mode
Routerconfiguration:G3(su)‐>router(Config‐router)#
Usage
Bydefault,RIPversion2supportsautomaticroutesummarization,whichsummarizes
subprefixestotheclassfulnetworkboundarywhencrossingnetworkboundaries.Disabling
automaticroutesummarizationenablesCIDR,allowingRIPtoadvertiseallsubnetsandhost
routinginformationontheG‐Seriesdevice.Toverifywhichroutesaresummarizedforan
interface,
usetheshowiproutecommandasdescribedin“showiproute”onpage15‐17.The
reverseofthecommandre‐enablesautomaticroutesummarization.Bydefault,RIPauto‐
summarizationaffectsbothRIPv1andRIPv2routes.
Example
ThisexampleshowshowtodisableRIPautomaticroutesummarization:
G3(su)->router(Config)#router rip
G3(su)->router(Config-router)#no auto-summary
split-horizon poison
Usethiscommandtoenableordisablesplithorizonpoison‐reve rsemodeforRIPpackets.Theno
formofthiscommanddisablessplithorizonpoisonreverse.
Syntax
split-horizon poison
no split-horizon poison
Parameters
None.
Defaults
None.
Mode
Routerconfiguration:G3(su)‐>router(Config‐router)#
Usage
Splithorizonpreventsanetworkfrombeingadvertisedoutthesameinterfaceitwasreceivedon.
Thisfunctionisdisabledbydefault.
Example
ThisexampleshowshowtodisablesplithorizonpoisonreverseforRIPpacketstransmittedon
theVLAN1interface:
G3(su)->router(Config)#router rip
G3(su)->Router1(Config-router)#no split-horizon poison
Note: This command is necessary for enabling CIDR for RIP on the G-Series device.