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Chapter 10. Enhanced Interior Gateway Protocol (EIGRP)

Chapter 10. Enhanced Interior Gateway Protocol (EIGRP)

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Scenario2

Symptom:Ithasbeenreportedthatusersonnetwork

192.168.4.0(R4'sE0network)cannotreachIPresourceson

network192.168.3.0(R3'sEthernet0network).

Objective:Youwillhaveresolvedthisissuewhenyoucan

successfullyping192.168.3.3fromR4.

Isolatetheproblem:Beginbyverifyingthatthereported

symptomsareanetworkissueinsteadofanend-user

configurationproblem.Youcandothisbyissuingapingfrom

R4toR3'sEthernet0interfaceof192.168.3.3,asshownin

Example17-13.



Example17-13VerifySymptombypingingonR4

to192.168.3.3

R4#ping192.168.3.3



Typeescapesequencetoabort.

Sending5,100-byteICMPEchosto192.168.3.3,timeoutis2sec

.....

Successrateis0percent(0/5)

R4#

Therequesthasfailed.Nowthatyouhaveverifiedtheproblem,

followtheprescribedtroubleshootingmethodologybystarting

atR4andverifyingLayer1,Layer2,andfinallyLayer3.

ExaminephysicalconnectivityonR4andverifythatEthernet0

andSerial0areupbydoingashowipinterfacesbrief,as

showninExample17-14.



Example17-14showipintbriefonR4Shows

ThatEthernet0andSerial0AreUp



R4#showipintbrief

InterfaceIP-AddressOK?MethodStatus

Ethernet0192.168.4.4YESNVRAMup

Loopback0192.169.4.4YESNVRAMup

Loopback1200.200.1.4YESNVRAMup

Loopback2200.200.2.4YESNVRAMup

Serial0192.168.100.4YESNVRAMup

Serial1unassignedYESunsetadministrativ

R4#

OfparticularconcernhereisEthernet0andSerial0becauseif

eitheroftheseinterfacesweredownorifthelineprotocolwere

down,youwouldhaveaLayer1or2issuetoresolve.However,

youcanseeinthehighlightedsectionsofExample17-14that

bothEthernet0andSerial0interfacesareupandthattheline

protocoloneachisup.Additionally,youcanverifythatR4's

PVCtoR3isACTIVEbydoingashowframe-relaypvc,as

showninExample17-15.



Example17-15R4'sPVCtoR3ShowsACTIVEas

Verifiedbyshowframe-relaypvcCommandonR4

R4#showframe-relaypvc

PVCStatisticsforinterfaceSerial0(FrameRelayDTE)



DLCI=101,DLCIUSAGE=LOCAL,PVCSTATUS=ACTIVE,INTERFACE



inputpkts12250outputpkts23980inbytes87

outbytes1677066droppedpkts0inFECNpkt

inBECNpkts0outFECNpkts0outBECNpk

inDEpkts0outDEpkts0



outbcastpkts23474outbcastbytes1619636

pvccreatetime3d18h,lasttimepvcstatuschanged2d16h

R4#

FromthehighlightedportionsofExample17-15,youseethat

thePVCtoR3isACTIVEandthatthePVChasbeenupfor2

daysand16hours,asshownbythelastPVCstatuschangein

theexample.Thus,tothispoint,youknowthatLayer1and2

appearasyouwouldexpectthemtoonR4.

Next,lookforaroutetothe192.168.3.0networkinR4's

routingtablebydoingashowiproute192.168.3.0onR4,as

showninExample17-16.



Example17-16Network192.168.3.0IsNotin

R4'sRoutingTable

R4#showiproute192.168.3.0

%Networknotintable

R4#

ItisapparentthatR4isnotreceivingthisroute.Ifyouexamine

theIProutingtableofR4,youcandeterminewhetheryouare

lackingjustthisonerouteorwhetheryouaren'tlearningroutes

toothernetworksasshowninExample17-17.



Example17-17RoutingTableShowsR4'sRoutes

toOtherNetworks



R4#showiproute

Codes:C-connected,S-static,I-IGRP,R-RIP,M-mobile

D-EIGRP,EX-EIGRPexternal,O-OSPF,IA-OSPFinte

N1-OSPFNSSAexternaltype1,N2-OSPFNSSAexternal

E1-OSPFexternaltype1,E2-OSPFexternaltype2,E

i-IS-IS,L1-IS-ISlevel-1,L2-IS-ISlevel-2,*-c



U-per-userstaticroute,o-ODR

Gatewayoflastresortisnotset



C200.200.1.0/24isdirectlyconnected,Loopback1

C200.200.2.0/24isdirectlyconnected,Loopback2

C192.168.100.0/24isdirectlyconnected,Serial0

DEX192.168.35.0/24[170/2169856]via192.168.100.3,02:03:34,

DEX192.168.60.0/24[170/41536000]via192.168.100.3,02:03:34

DEX192.168.50.0/24[170/2697984]via192.168.100.3,02:03:34,

DEX192.169.1.0/24[170/2733056]via192.168.100.3,01:48:05,

DEX192.168.1.0/24[170/2733056]via192.168.100.3,01:48:05,

DEX192.168.2.0/24[170/2733056]via192.168.100.3,01:48:05,

DEX192.169.3.0/24[170/2169856]via192.168.100.3,02:03:34,

DEX192.169.2.0/24[170/2733056]via192.168.100.3,01:48:06,

DEX192.169.5.0/24[170/2809856]via192.168.100.3,02:03:35,

192.168.4.0/27issubnetted,1subnets

C192.168.4.0isdirectlyconnected,Ethernet0

C192.169.4.0/24isdirectlyconnected,Loopback0

DEX192.168.200.0/24[170/41536000]via192.168.100.3,02:03:3

D200.200.0.0/16isasummary,02:03:38,Null0

R4#

YoucanseethatallEIGRProuteshavebeenlearnedthrough

192.168.100.3,ashighlighted.ThistellsyouthatR3'sSerial0

interfaceandtheFrameRelayPVCmustbeuptobe

propagatingtheseroutestoR4.Referbacktotherouting

protocoldiagraminFigure17-1.

Network192.168.3.0shouldbeapartofEIGRPAS100.

Becauseitisnotbeingpropagated,youmighthaveanEIGRP

configurationissueonR3orEthernet0onR3couldbedown,

causingtheroutenottobeadvertisedbyEIGRP.Ensurethat

Ethernet0isuponR3bydoingashowipinterfacebrief,as

demonstratedinExample17-18.



Example17-18VerifyThatEthernet0onR3Isup



UsingtheshowipinterfacebriefCommand



R3#showipinterfacebrief

InterfaceIP-AddressOK?MethodStatus

Ethernet0192.168.3.3YESNVRAMup

Loopback0192.169.3.3YESNVRAMup

Serial0192.168.100.3YESNVRAMup

Serial1192.168.35.3YESNVRAMup

R3#

BecauseR3'sEthernet0interfaceisupandthelineprotocolis

up,youmightsuspecttheissuetobewiththeEIGRP

configurationofR3.Doashowipeigrpinterfacestosee

whichinterfacesonR3arepartofEIGRPAS100,as

demonstratedinExample17-19.



Example17-19ExamineWhichInterfacesArea

PartofEIGRP100Usingtheshowipeigrp

interfacesCommandonR3

R3#showipeigrpinterfaces

IP-EIGRPinterfacesforprocess100



XmitQueueMeanPacingTimeMulticast

InterfacePeersUn/ReliableSRTTUn/ReliableFlowTime

Se020/0910/15262

R3#

YoucanseethatSerial0isapartofEIGRPprocess(AS)100,

butR3'sEthernet0isnot.Atthispoint,theEIGRPconfiguration

isdefinitelysuspect.ExaminetherunningconfigofR3,as

showninExample17-20.



Example17-20ExaminetheRunning



ConfigurationonR3

R3#showrunning-config

Buildingconfiguration...



Currentconfiguration:

!

version11.2

noservicepassword-encryption

noserviceudp-small-servers

noservicetcp-small-servers

!

hostnameR3

!

enablepasswordfalcons

!

usernameall

noipdomain-lookup

iphostR3192.169.3.3

iphostR1192.169.1.1

iphostR2192.169.2.2

iphostR4192.169.4.4

iphostR5192.169.5.5

iphostR6192.169.6.6

ipxrouting0000.0000.3333

!

interfaceLoopback0

ipaddress192.169.3.3255.255.255.0

!

interfaceEthernet0

ipaddress192.168.3.3255.255.255.0

ipxnetwork3000

ipxnetwork3001encapsulationSAPsecondary

!

interfaceSerial0

descriptionThisinterfaceconnectstoR2'sS0(DLCI200)andR



ipaddress192.168.100.3255.255.255.0

ipaccess-group101in

encapsulationframe-relay

noipsplit-horizoneigrp100

ipxnetwork1000

noipxsplit-horizoneigrp100

nofair-queue

frame-relaylmi-typeansi

!

interfaceSerial1

descriptionThisinterfaceconnectstoR5'sS0(DCE)

ipaddress192.168.35.3255.255.255.0

ipxnetwork3500

!

routereigrp100

redistributeigrp200metric20020025511500

network192.168.100.0

!

routerigrp200

redistributeeigrp100metric200020025511500

network192.168.35.0

network192.169.3.0

!

noipclassless

access-list101denytcpany192.168.50.00.0.0.255eqwww

access-list101denytcpany192.168.30.00.0.0.255eqftp

access-list101denytcpany192.168.30.00.0.0.255eqftp-da

access-list101permitipanyany

!

!

!

ipxroutereigrp100

network1000

!

!

ipxrouterrip

nonetwork1000



!

!

!

bannermotd^C

ThisisRouter3

^C

!

linecon0

exec-timeout00

passwordfalcons

loggingsynchronous

lineaux0

linevty04

passwordfalcons

login

!

end

R3#

InExample17-20,theEIGRPconfigurationhasbeen

highlighted.Noticethatnetwork192.168.3.0isnotapartof

EIGRPAS100.Itsureisdifficulttogetgoodhelpthesedays.

Someonemusthaveincorrectlyremovedthisnetworkfrom

EIGRP.CorrectthiserrorbyaddingthenetworkbackintoEIGRP

AS100,savingtheconfiguration,andthendoingashowip

eigrpinterfaces,asshowninExample17-21.



Example17-21AddingNetwork192.168.3.0Back

intoEIGRP100,SavingConfiguration,andThen

VerifyConfigurationUsingshowipeigrp

interfacesCommandonR3

R3#conft

Enterconfigurationcommands,oneperline.EndwithCNTL/Z.

R3(config)#routereigrp100



R3(config-router)#network192.168.3.0

R3(config-router)#^Z

R3#

%SYS-5-CONFIG_I:Configuredfromconsolebyconsole

R3#copyrunstart

Buildingconfiguration...

[OK]

R3#shoipeigrpint

IP-EIGRPinterfacesforprocess100

XmitQueueMeanPacingTimeMulticast

InterfacePeersUn/ReliableSRTTUn/ReliableFlowTime

Se020/01140/1550

Et000/000/100

R3#

NowyouseethatR3'sEthernet0networkof192.168.3.0is

beingadvertisedinEIGRPprocess100.YoucanverifythatR4

receivesthisrouteasyouexpectbyreturningtoR4anddoinga

showiproute192.168.3.0,asdemonstratedinExample1722.



Example17-22showiproute192.168.3.0Now

ShowsThatR4IsReceivingThisRoute



R4#showiproute192.168.3.0

Routingentryfor192.168.3.0/24

Knownvia"eigrp100",distance90,metric2195456,typeinte

Redistributingviaeigrp100

Lastupdatefrom192.168.100.3onSerial0,00:04:15ago

RoutingDescriptorBlocks:

*192.168.100.3,from192.168.100.3,00:04:15ago,viaSerial

Routemetricis2195456,trafficsharecountis1

Totaldelayis21000microseconds,minimumbandwidthis1

Reliability255/255,minimumMTU1500bytes

Loading1/255,Hops1



R4#

R4hasnowreceivedthisroute,whichwaslearnedthrough

192.168.100.3,ashighlighted.Nowping192.168.3.3fromR4,

asshowninExample17-23.



Example17-23Successfulpingto192.168.3.3

R4#ping192.168.3.3



Typeescapesequencetoabort.

Sending5,100-byteICMPEchosto192.168.3.3,timeoutis2sec

!!!!!

Successrateis100percent(5/5),round-tripmin/avg/max=60/

R4#

Yougot100percentsuccess!Youhavesuccessfullyresolved

thisissue.









Top











IPXRoutingFundamentals

WithinCiscoIOSSoftware,IPXcanberoutedusingthree

possibleroutingprotocols:

IPXRIP

IPXEIGRP

NetwareLinkServicesProtocol(NLSP)



NLSPisalink-stateprotocoldevelopedbyNovellbasedonthe

ISOIntermediateSystem-to-IntermediateSystem(IS-IS)

routingprotocol.NLSPisbeyondthescopeofthisbook,sothe

focuswillbelimitedtoIPXRIPandIPXEIGRP.Additional

informationregardingNLSPanditsconfigurationcanbefound

onCCOat

www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/atipx



IPXRIP

NovellRIP,commonlyknownasIPXRIP,isadistancevector

routingprotocolandisthedefaultroutingprotocolforIPX.IPX

RIPusestwometricstomakeroutingdecisions:ticks(atime

measureequalto1/18second)andhopcount(acountofeach

routertraversed),toamaximumof15.IPXRIPchecksitstwo

distancevectormetricsbyfirstcomparingtheticksforpath

alternatives.Iftwoormorepathshavethesametickvalue,IPX

RIPcomparesthehopcount.EachIPXrouterperiodically

broadcastscopiesofitsIPXRIProutingtabletoitsdirectly

connectednetworks.TheneighboringIPXroutersincrementthe



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