Chapter 9 Chapter 9

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Chapter 9
Chapter 9
Enhanced Interior Gateway
Enhanced Interior Gateway
Routing Protocol (EIGRP)
Routing Protocol (EIGRP)
Part I
Part I
Chapter 9-2
CCNA2-1
Note for Instructors
Note for Instructors
• These presentations are the result of a collaboration among
• These presentations are the result of a collaboration among
tth he e iin ns sttr ru uc ctto or rs s a att S Stt.. C Clla aiir r C Co olllle eg ge e iin n W Wiin nd ds so or r,, O On ntta ar riio o..
•• T Th ha an nk ks s m mu us stt g go o o ou utt tto o R Riic ck k G Gr ra az ziia an nii o off C Ca ab br riillllo o C Co olllle eg ge e.. H Hiis s
material and additional information was used as a reference
material and additional information was used as a reference
iin n tth he eiir r c cr re ea attiio on n..
•• IIff a an ny yo on ne e ffiin nd ds s a an ny y e er rr ro or rs s o or r o om miis ss siio on ns s,, p plle ea as se e lle ett m me e k kn no ow w
at:
at:
• tdame@stclaircollege.ca.
• tdame@stclaircollege.ca.
CCNA2-2 Chapter 9-2E EIIG GR RP P
DUAL
DUAL
Chapter 9-2
CCNA2-3
DUAL Concepts
DUAL Concepts
• Diffusing Update ALgorithm (DUAL) provides the following:
• Diffusing Update ALgorithm (DUAL) provides the following:
• • L Lo oo op p- -ffr re ee e p pa atth hs s..
• • L Lo oo op p- -ffr re ee e b ba ac ck ku up p p pa atth hs s w wh hiic ch h c ca an n b be e u us se ed d iim mm me ed diia atte elly y..
• • F Fa as stt c co on nv ve er rg ge en nc ce e..
• Minimum bandwidth usage with bounded updates.
• Minimum bandwidth usage with bounded updates.
CCNA2-4 Chapter 9-2D DU UA AL L C Co on nc ce ep ptts s
•• D Diiffffu us siin ng g U Up pd da atte e A AL Lg go or riitth hm m ( (D DU UA AL L) ) u us se es s s se ev ve er ra all tte er rm ms s tth ha att
w we e w wiillll d diis sc cu us ss s iin n m mo or re e d de etta aiill tth hr ro ou ug gh ho ou utt tth hiis s s se ec cttiio on n::
• Successor.
• Successor.
• Feasible distance.
• Feasible distance.
• • F Fe ea as siib blle e s su uc cc ce es ss so or r..
• • R Re ep po or rtte ed d d diis stta an nc ce e o or r a ad dv ve er rttiis se ed d d diis stta an nc ce e..
• Feasible condition or feasibility condition.
• Feasible condition or feasibility condition.
Chapter 9-2
CCNA2-5
Successor and Feasible Distance
Successor and Feasible Distance
• A successor is:
• A successor is:
• • A A n ne eiig gh hb bo or riin ng g r ro ou utte er r tth ha att iis s u us se ed d ffo or r p pa ac ck ke ett ffo or rw wa ar rd diin ng g..
• • T Th he e lle ea as stt- -c co os stt r ro ou utte e tto o tth he e d de es sttiin na attiio on n n ne ettw wo or rk k..
•• T Th he e IIP P a ad dd dr re es ss s o off a a s su uc cc ce es ss so or r iis s s sh ho ow wn n iin n a a r ro ou uttiin ng g tta ab blle e
entry right after the word via.
entry right after the word via.
CCNA2-6 Chapter 9-2S Su uc cc ce es ss so or r a an nd d F Fe ea as siib blle e D Diis stta an nc ce e
•• F Fe ea as siib blle e D Diis stta an nc ce e ( (F FD D) )::
• • IIs s tth he e llo ow we es stt c ca allc cu ulla atte ed d m me ettr riic c tto o r re ea ac ch h tth he e d de es sttiin na attiio on n
network.
network.
• Feasible Distance is listed in the routing table entry as the
• Feasible Distance is listed in the routing table entry as the
s se ec co on nd d n nu um mb be er r iin ns siid de e tth he e b br ra ac ck ke etts s..
• As with other routing protocols, this is the metric for the
• As with other routing protocols, this is the metric for the
r ro ou utte e..
Chapter 9-2
CCNA2-7
Feasible Successors
Feasible Successors
• One of the reasons DUAL can converge quickly after a
• One of the reasons DUAL can converge quickly after a
c ch ha an ng ge e iin n tth he e tto op po ollo og gy y iis s b be ec ca au us se e iitt c ca an n u us se e b ba ac ck ku up p p pa atth hs s tto o
o otth he er r r ro ou utte er rs s k kn no ow wn n a as s ffe ea as siib blle e s su uc cc ce es ss so or rs s w wiitth ho ou utt h ha av viin ng g tto o
re-compute DUAL.
re-compute DUAL.
CCNA2-8 Chapter 9-2F Fe ea as siib blle e S Su uc cc ce es ss so or rs s
Successor
Successor
Feasible Successor
Feasible Successor
Route
Route
Route
Route
•• A A F Fe ea as siib blle e S Su uc cc ce es ss so or r ( (F FS S) ) iis s a a n ne eiig gh hb bo or r w wh ho o h ha as s a a llo oo op p- -ffr re ee e
b ba ac ck ku up p p pa atth h tto o tth he e s sa am me e n ne ettw wo or rk k a as s tth he e s su uc cc ce es ss so or r..
Chapter 9-2
CCNA2-9
Feasibility Condition and Reported Distance
Feasibility Condition and Reported Distance
F Fe ea as siib blle e S Su uc cc ce es ss so or r
• How does a route become
• How does a route become
R Ro ou utte e
a a F Fe ea as siib blle e S Su uc cc ce es ss so or r? ?
• • IItt m mu us stt m me ee ett tth he e
Feasibility Condition.
Feasibility Condition.
•• F Fe ea as siib biilliitty y C Co on nd diittiio on n ( (F FC C) )::
• • T Th he e F FC C iis s m me ett w wh he en n a a n ne eiig gh hb bo or r’’s s R Re ep po or rtte ed d D Diis stta an nc ce e tto o a a
network is less than the local router’s Feasible Distance
network is less than the local router’s Feasible Distance
tto o tth he e s sa am me e d de es sttiin na attiio on n n ne ettw wo or rk k..
CCNA2-10 Chapter 9-2F Fe ea as siib biilliitty y C Co on nd diittiio on n a an nd d R Re ep po or rtte ed d D Diis stta an nc ce e
Both R1 and R2 have
Both R1 and R2 have
loop-free Successor
loop-free Successor
R Ro ou utte es s tto o tth he e s sa am me e
destination network.
destination network.
Chapter 9-2
CCNA2-11
Feasibility Condition and Reported Distance
Feasibility Condition and Reported Distance
R R1 1 s se en nd ds s a an n u up pd da atte e
to R2 that includes
to R2 that includes
iitts s m me ettr riic c ( (F FD D) )..
CCNA2-12 Chapter 9-2F Fe ea as siib biilliitty y C Co on nd diittiio on n a an nd d R Re ep po or rtte ed d D Diis stta an nc ce e
FD to 192.168.1.0/24
FD to 192.168.1.0/24
RD to 192.168.1.0/24
RD to 192.168.1.0/24
R2 considers R1’s metric
R2 considers R1’s metric
as a Reported Distance
as a Reported Distance
RD is less than the FD.
RD is less than the FD.
tto o tth he e s sa am me e n ne ettw wo or rk k..
Feasibility Condition met.
Feasibility Condition met.
Chapter 9-2
CCNA2-13
Feasibility Condition and Reported Distance
Feasibility Condition and Reported Distance
F FD D tto o 1 19 92 2..1 16 68 8..1 1..0 0//2 24 4
R RD D tto o 1 19 92 2..1 16 68 8..1 1..0 0//2 24 4
R R2 2 a ad dd ds s tth he e r ro ou utte e ffr ro om m R R1 1
to the topology table as the
to the topology table as the
F Fe ea as siib blle e S Su uc cc ce es ss so or r r ro ou utte e tto o
n ne ettw wo or rk k 1 19 92 2..1 16 68 8..1 1..0 0//2 24 4..
CCNA2-14 Chapter 9-2T To op po ollo og gy y T Ta ab blle e
•• S Su uc cc ce es ss so or r a an nd d F Fe ea as siib blle e S Su uc cc ce es ss so or r::
• • T Th he e S Su uc cc ce es ss so or r,, F Fe ea as siib blle e D Diis stta an nc ce e,, a an nd d a an ny y F Fe ea as siib blle e
Successors with their Reported Distances are kept by a
Successors with their Reported Distances are kept by a
r ro ou utte er r iin n iitts s E EIIG GR RP P tto op po ollo og gy y tta ab blle e..
Chapter 9-2
CCNA2-15
Topology Table: Successor
Topology Table: Successor
T Tw wo o S Stta atte es s::
Active (A): Being recalculated by DUAL.
Active (A): Being recalculated by DUAL.
P Pa as ss siiv ve e ( (P P) ):: A A s stta ab blle e s su uc cc ce es ss so or r r ro ou utte e..
D De es sttiin na attiio on n N Ne ettw wo or rk k
F Fe ea as siib blle e D Diis stta an nc ce e tto o S Su uc cc ce es ss so or r
N Nu um mb be er r o off S Su uc cc ce es ss so or rs s
CCNA2-16 Chapter 9-2T To op po ollo og gy y T Ta ab blle e:: S Su uc cc ce es ss so or r
Next Hop address for Successor
Next Hop address for Successor
R3’s Reported Distance
R3’s Reported Distance
Outbound Physical
Outbound Physical
Interface
Interface
Chapter 9-2
CCNA2-17
Topology Table: Feasible Successor
Topology Table: Feasible Successor
N Ne ex xtt H Ho op p a ad dd dr re es ss s ffo or r F Fe ea as siib blle e S Su uc cc ce es ss so or r
F Fe ea as siib blle e S Su uc cc ce es ss so or r’’s s R Re ep po or rtte ed d D Diis stta an nc ce e
R R2 2’’s s n ne ew w F FD D tto o
P Ph hy ys siic ca all IIn ntte er rffa ac ce e
192.168.1.0/24 if R1
192.168.1.0/24 if R1
b be ec ca am me e tth he e F Fe ea as siib blle e
S Su uc cc ce es ss so or r..
CCNA2-18 Chapter 9-2T To op po ollo og gy y T Ta ab blle e:: N NO O F Fe ea as siib blle e S Su uc cc ce es ss so or r
•• T Th he e a ab bo ov ve e iis s a a p po or rttiio on n o off R R1 1’’s s tto op po ollo og gy y tta ab blle e tth ha att s sh ho ow ws s iitts s
lliin nk k tto o n ne ettw wo or rk k 1 19 92 2..1 16 68 8..1 1..0 0//2 24 4..
• Why has R2’s route NOT become the feasible successor
• Why has R2’s route NOT become the feasible successor
ffo or r R R1 1? ?
• • IItt d do oe es s n no ott m me ee ett tth he e F Fe ea as siib biilliitty y C Co on nd diittiio on n..
• EIGRP is a distance vector routing protocol and only knows
• EIGRP is a distance vector routing protocol and only knows
a ab bo ou utt r re em mo otte e n ne ettw wo or rk k iin nffo or rm ma attiio on n tth hr ro ou ug gh h iitts s n ne eiig gh hb bo or rs s..
Chapter 9-2
CCNA2-19
Finite State Machine (DUAL FSM)
Finite State Machine (DUAL FSM)
• The centerpiece of EIGRP is DUAL and its EIGRP route-
• The centerpiece of EIGRP is DUAL and its EIGRP route-
c ca allc cu ulla attiio on n e en ng giin ne e – – tth he e F Fiin niitte e S Stta atte e M Ma ac ch hiin ne e..
•• T Th hiis s F FS SM M c co on ntta aiin ns s a allll tth he e llo og giic c u us se ed d tto o c ca allc cu ulla atte e a an nd d
compare routes in an EIGRP network.
compare routes in an EIGRP network.
CCNA2-20 Chapter 9-2F Fiin niitte e S Stta atte e M Ma ac ch hiin ne e ( (D DU UA AL L F FS SM M) )
•• W Wh ha att iis s F FS SM M? ?
• • A An n F FS SM M iis s a an n a ab bs sttr ra ac ctt m ma ac ch hiin ne e,, n no ott a a m me ec ch ha an niic ca all d de ev viic ce e
with moving parts.
with moving parts.
• FSMs define a set of possible states something can go
• FSMs define a set of possible states something can go
tth hr ro ou ug gh h,, w wh ha att e ev ve en ntts s c ca au us se es s tth ho os se e s stta atte es s,, a an nd d w wh ha att
events result from those states.
events result from those states.
• • D De es siig gn ne er rs s u us se e F FS SM Ms s tto o d de es sc cr riib be e h ho ow w a a d de ev viic ce e,, c co om mp pu utte er r
p pr ro og gr ra am m,, o or r r ro ou uttiin ng g a allg go or riitth hm m w wiillll r re ea ac ctt tto o a a s se ett o off iin np pu utt
events.
events.
Chapter 9-2
CCNA2-21
EIGRP
EIGRP
More EIGRP Configurations
More EIGRP Configurations
N Nu ullll0 0 S Su um mm ma ar ry y R Ro ou utte e
D Diis sa ab blle e A Au utto om ma attiic c S Su um mm ma ar riiz za attiio on n
M Ma an nu ua all S Su um mm ma ar riiz za attiio on n
E EIIG GR RP P D De effa au ulltt R Ro ou utte e
CCNA2-22 Chapter 9-2T Th he e N Nu ullll0 0 S Su um mm ma ar ry y R Ro ou utte e
•• E EIIG GR RP P a au utto om ma attiic ca alllly y iin nc cllu ud de es s a a N Nu ullll0 0 s su um mm ma ar ry y r ro ou utte e a as s a a
c ch hiilld d r ro ou utte e w wh he en ne ev ve er r b bo otth h o off tth he e ffo ollllo ow wiin ng g c co on nd diittiio on ns s e ex xiis stt::
• There is at least one subnet that was learned via EIGRP.
• There is at least one subnet that was learned via EIGRP.
• Automatic summarization is enabled (default).
• Automatic summarization is enabled (default).
•• R R1 1 w wiillll d diis sc ca ar rd d a an ny y p pa ac ck ke etts s tth ha att m ma attc ch h tth he e p pa ar re en ntt c clla as ss sffu ull
network but do not match one of the child routes.
network but do not match one of the child routes.
Chapter 9-2
CCNA2-23
The Null0 Summary Route
The Null0 Summary Route
• You might think that if you configure classless routing
• You might think that if you configure classless routing
b be eh ha av viio or r w wiitth h tth he e iipp ccllaasssslleessss c co om mm ma an nd d,, E EIIG GR RP P w wo ou ulld d
n no ott d diis sc ca ar rd d tth ha att p pa ac ck ke ett b bu utt w wo ou ulld d c co on nttiin nu ue e llo oo ok kiin ng g ffo or r a a
default or supernet route.
default or supernet route.
•• T Th hiis s N Nu ullll0 0 s su um mm ma ar ry y r ro ou utte e iis s a a c ch hiilld d r ro ou utte e tth ha att w wiillll m ma attc ch h a an ny y
p po os ss siib blle e p pa ac ck ke etts s o off tth he e p pa ar re en ntt r ro ou utte e r re eg ga ar rd dlle es ss s o off tth he e
iipp ccllaasssslleessss // nnoo iipp ccllaasssslleessss c co om mm ma an nd d..
CCNA2-24 Chapter 9-2D Diis sa ab blliin ng g A Au utto om ma attiic c S Su um mm ma ar riiz za attiio on n
Both R1 and R2
Both R1 and R2
automatically summarized
automatically summarized
172.16.0.0/16
172.16.0.0/16
tth he e s su ub bn ne etts s a an nd d s se en ntt a an n
update to R3.
update to R3.
172.16.0.0/16
172.16.0.0/16
•• L Liik ke e R RIIP P,, E EIIG GR RP P a au utto om ma attiic ca alllly y s su um mm ma ar riiz ze es s a att m ma ajjo or r n ne ettw wo or rk k
boundaries using the defaultauto-summary command.
boundaries using the defaultauto-summary command.
Chapter 9-2
CCNA2-25
Disabling Automatic Summarization
Disabling Automatic Summarization
• The result is that R3 has one route to 172.16.0.0/16
• The result is that R3 has one route to 172.16.0.0/16
tth hr ro ou ug gh h R R1 1..
•• R R1 1 iis s tth he e s su uc cc ce es ss so or r b be ec ca au us se e o off tth he e d diiffffe er re en nc ce e iin n b ba an nd dw wiid dtth h..
CCNA2-26 Chapter 9-2D Diis sa ab blliin ng g A Au utto om ma attiic c S Su um mm ma ar riiz za attiio on n
•• R R3 3 w wiillll r ro ou utte e a allll p pa ac ck ke etts s d de es sttiin ne ed d ffo or r 1 17 72 2..1 16 6..2 2..0 0 tth hr ro ou ug gh h R R1 1..
•• R R3 3 d do oe es s n no ott k kn no ow w tth ha att R R1 1 w wiillll tth he en n h ha av ve e tto o r ro ou utte e tth he es se e
packets across a very slow link to R2 (64 Kbps).
packets across a very slow link to R2 (64 Kbps).
Chapter 9-2
CCNA2-27
Disabling Automatic Summarization
Disabling Automatic Summarization
IIn n o otth he er r w wo or rd ds s,, R R1 1 a an nd d R R2 2
must stop automatically
must stop automatically
s su um mm ma ar riiz ziin ng g
1 17 72 2..1 16 6..0 0..0 0//1 16 6..
• The only way R3 can learn about this slow bandwidth is if R1
• The only way R3 can learn about this slow bandwidth is if R1
a an nd d R R2 2 s se en nd d iin nd diiv viid du ua all r ro ou utte es s ffo or r e ea ac ch h o off tth he e 1 17 72 2..1 16 6..0 0..0 0//1 16 6
s su ub bn ne etts s..
CCNA2-28 Chapter 9-2D Diis sa ab blliin ng g A Au utto om ma attiic c S Su um mm ma ar riiz za attiio on n
R2(config)# router eigrp 1
R2(config)# router eigrp 1
R2(config-router)# no auto-summary
R2(config-router)# no auto-summary
R1(config)# router eigrp 1
R1(config)# router eigrp 1
R1(config-router)# no auto-summary
R1(config-router)# no auto-summary
R3(config)# router eigrp 1
R3(config)# router eigrp 1
R3(config-router)# no auto-summary
R3(config-router)# no auto-summary
•• A Au utto om ma attiic c s su um mm ma ar riiz za attiio on n c ca an n b be e d diis sa ab blle ed d w wiitth h tth he e
no auto-summary command.
no auto-summary command.
Chapter 9-2
CCNA2-29
Disabling Automatic Summarization
Disabling Automatic Summarization
B Be effo or re e
A Afftte er r
• Without automatic summarization, R3’s routing table now
• Without automatic summarization, R3’s routing table now
iin nc cllu ud de es s tth he e tth hr re ee e s su ub bn ne etts s..
CCNA2-30 Chapter 9-2M Ma an nu ua all S Su um mm ma ar riiz za attiio on n
•• E EIIG GR RP P c ca an n b be e c co on nffiig gu ur re ed d tto o s su um mm ma ar riiz ze e r ro ou utte es s,, w wh he etth he er r o or r
n no ott a au utto om ma attiic c s su um mm ma ar riiz za attiio on n iis s e en na ab blle ed d..
• Modify the topology to add two more networks to R3.
• Modify the topology to add two more networks to R3.
Chapter 9-2
CCNA2-31
Manual Summarization
Manual Summarization
RR11## sshhooww iipp rroouuttee
DD 119922..116688..11..00//2244 [[9900//22117722441166]] vviiaa 119922..116688..1100..66,, 0022::0077::3388,, SS00//00//11
D 192.168.2.0/24 [90/2297856] via 192.168.10.6, 00:00:34, S0/0/1
D 192.168.2.0/24 [90/2297856] via 192.168.10.6, 00:00:34, S0/0/1
DD 119922..116688..33..00//2244 [[9900//22229977885566]] vviiaa 119922..116688..1100..66,, 0000::0000::1188,, SS00//00//11
• Instead of sending three separate networks, R3 can
• Instead of sending three separate networks, R3 can
s su um mm ma ar riiz ze e tth he e 1 19 92 2..1 16 68 8..1 1..0 0//2 24 4,, 1 19 92 2..1 16 68 8..2 2..0 0//2 24 4,, a an nd d
1 19 92 2..1 16 68 8..3 3..0 0//2 24 4 n ne ettw wo or rk ks s a as s a a s siin ng glle e r ro ou utte e..
CCNA2-32 Chapter 9-2M Ma an nu ua all S Su um mm ma ar riiz za attiio on n
•• W Wr riitte e o ou utt tth he e n ne ettw wo or rk ks s tth ha att y yo ou u w wa an ntt tto o s su um mm ma ar riiz ze e iin n b biin na ar ry y..
•• F Fiin nd d tth he e m ma attc ch hiin ng g b biitts s..
• Count the number of leftmost matching bits, which in this
• Count the number of leftmost matching bits, which in this
example is 22.
example is 22.
•• T Th hiis s n nu um mb be er r b be ec co om me es s y yo ou ur r s su ub bn ne ett m ma as sk k ffo or r tth he e s su um mm ma ar riiz ze ed d
route ( /22 or 255.255.252.0) .
route ( /22 or 255.255.252.0) .
• To find the network address for summarization, copy the
• To find the network address for summarization, copy the
m ma attc ch hiin ng g 2 22 2 b biitts s a an nd d a ad dd d a allll 0 0 b biitts s tto o tth he e e en nd d tto o m ma ak ke e 3 32 2 b biitts s..
•• T Th he e r re es su ulltt iis s tth he e s su um mm ma ar ry y n ne ettw wo or rk k a ad dd dr re es ss s a an nd d m ma as sk k ffo or r
192.168.0.0/22
192.168.0.0/22
Chapter 9-2
CCNA2-33
Configure EIGRP Manual Summarization
Configure EIGRP Manual Summarization
• Because R3 has two EIGRP neighbours, EIGRP manual
• Because R3 has two EIGRP neighbours, EIGRP manual
s su um mm ma ar riiz za attiio on n iis s c co on nffiig gu ur re ed d o on n b bo otth h s se er riia all iin ntte er rffa ac ce es s a an nd d w wiillll
b be e p pr ro op pa ag ga atte ed d tto o tth he e n ne eiig gh hb bo ou ur rs s..
CCNA2-34 Chapter 9-2E EIIG GR RP P D De effa au ulltt R Ro ou utte e
•• U Us siin ng g a a s stta attiic c r ro ou utte e tto o 0 0..0 0..0 0..0 0//0 0 a as s a a d de effa au ulltt r ro ou utte e iis s n no ott
r ro ou uttiin ng g p pr ro otto oc co oll d de ep pe en nd de en ntt..
• EIGRP requires the use of the redistribute static
• EIGRP requires the use of the redistribute static
c co om mm ma an nd d tto o iin nc cllu ud de e tth hiis s s stta attiic c d de effa au ulltt r ro ou utte e w wiitth h iitts s u up pd da atte es s..
Chapter 9-2
CCNA2-35
EIGRP Default Route
EIGRP Default Route
CCNA2-36 Chapter 9-2E EIIG GR RP P D De effa au ulltt R Ro ou utte e
•• IIn n tth he e r ro ou uttiin ng g tta ab blle es s ffo or r R R1 1 a an nd d R R3 3,, n no ottiic ce e tth he e r ro ou uttiin ng g s so ou ur rc ce e
a an nd d A AD D ffo or r tth he e n ne ew w s stta attiic c d de effa au ulltt r ro ou utte e..
• D - This static route was learned from an EIGRP routing
• D - This static route was learned from an EIGRP routing
u up pd da atte e..
• • * * - - T Th he e r ro ou utte e iis s a a c ca an nd diid da atte e ffo or r a a d de effa au ulltt r ro ou utte e..
• EX - The route is an external EIGRP route, in this case a
• EX - The route is an external EIGRP route, in this case a
s stta attiic c r ro ou utte e o ou utts siid de e o off tth he e E EIIG GR RP P r ro ou uttiin ng g d do om ma aiin n..
• • 1 17 70 0 - - T Th hiis s iis s tth he e A AD D o off a an n e ex xtte er rn na all E EIIG GR RP P r ro ou utte e..
Chapter 9-2
CCNA2-37
Fine-Tuning EIGRP
Fine-Tuning EIGRP
• By default, EIGRP uses only up to 50 percent of the
• By default, EIGRP uses only up to 50 percent of the
b ba an nd dw wiid dtth h o off a an n iin ntte er rffa ac ce e ffo or r E EIIG GR RP P iin nffo or rm ma attiio on n..
•• T Th hiis s p pr re ev ve en ntts s tth he e E EIIG GR RP P p pr ro oc ce es ss s ffr ro om m o ov ve er r- -u uttiilliiz ziin ng g a a lliin nk k
and not allowing enough bandwidth for the routing of normal
and not allowing enough bandwidth for the routing of normal
ttr ra affffiic c..
• The ip bandwidth-percent eigrp command can be
• The ip bandwidth-percent eigrp command can be
used to configure the percentage of bandwidth that may be
used to configure the percentage of bandwidth that may be
u us se ed d b by y E EIIG GR RP P o on n a an n iin ntte er rffa ac ce e..
CCNA2-38 Chapter 9-2F Fiin ne e- -T Tu un niin ng g E EIIG GR RP P
•• W We e c ca an n lliim miitt E EIIG GR RP P tto o n no o m mo or re e tth ha an n 5 50 0 p pe er rc ce en ntt o off tth he e
6 64 4 K Kb bp ps s lliin nk k’’s s b ba an nd dw wiid dtth h b by y c co on nffiig gu ur riin ng g tth he e ffo ollllo ow wiin ng g o on n R R1 1
and R2.
and R2.
Chapter 9-2
CCNA2-39
Hello Intervals and Hold times
Hello Intervals and Hold times
• Hello intervals and hold times are configurable on a per-
• Hello intervals and hold times are configurable on a per-
iin ntte er rffa ac ce e b ba as siis s a an nd d d do o n no ott h ha av ve e tto o m ma attc ch h w wiitth h o otth he er r E EIIG GR RP P
r ro ou utte er rs s tto o e es stta ab blliis sh h a ad djja ac ce en nc ciie es s..
• The seconds value for both hello and holdtime intervals
• The seconds value for both hello and holdtime intervals
c ca an n r ra an ng ge e ffr ro om m 1 1 tto o 6 65 5,,5 53 35 5
•• IIff y yo ou u c ch ha an ng ge e tth he e h he ellllo o iin ntte er rv va all,, m ma ak ke e s su ur re e tth ha att y yo ou u a alls so o
change the hold time to a value equal to or greater than the
change the hold time to a value equal to or greater than the
h he ellllo o iin ntte er rv va all..
•• O Otth he er rw wiis se e,, n ne eiig gh hb bo or r a ad djja ac ce en nc cy y w wiillll g go o d do ow wn n a afftte er r tth he e h ho olld d
time expires and before the next hello interval.
time expires and before the next hello interval.
CCNA2-40 Chapter 9-2