Deploy Eigrp
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Deploying IGRP/E-IGRPDeploying IGRP/E-IGRP
Session 2208Session 2208
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Understanding E-IGRPUnderstanding E-IGRP
Understanding and deployingE-IGRP is like driving a car
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AgendaAgenda
Fundamentals of E-IGRP
DUAL
Summarization and Load Balancing
Query Process
Deployment Guidelines with E-IGRP
Summary
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IGRP: Interior GatewayRouting Protocol
IGRP: Interior GatewayRouting Protocol
Cisco proprietary
Distance vector
Broadcast based Utilizes link bandwidth and delay
15 hops is no longer the limit
90 seconds updates (RIP is 30 sec.)
Load balance over unequal cost paths
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IGRP/E-IGRP Metrics CalculationIGRP/E-IGRP Metrics Calculation
Metric = [K1 x BW + (K2 x BW) / (256 - Load) +K3 x Delay] x [K5 / (Reliability + K4)]
By Default: K1 = 1, K2 = 0, K3 = 1, K4 = K5 = 0
Delay is sum of all the delays of the link alongthe paths
Delay = Delay/10
Bandwidth is the lowest bandwidth of the linkalong the paths
Bandwidth = 10000000/Bandwidth
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Problems with RIP and IGRPProblems with RIP and IGRP
Slow convergence
Not 100% loop free
Dont support VLSM anddiscontiguous network
Periodic full routing updates
RIP has hop count limitation
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Advantages of E-IGRPAdvantages of E-IGRP
Advanced distance vector
100% loop free
Fast convergence
Easy configuration
Less network design constraints than OSPF
Incremental update
Supports VLSM and discontiguous network
Classless routing
Compatible with existing IGRP network
Protocol independent (support IPX and AppleTalk)
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Advantages of E-IGRPAdvantages of E-IGRP
Uses multicast instead of broadcast
Utilize link bandwidth and delayE-IGRP Metric = IGRP Metric x 256(32 bit Vs. 24 bit)
Unequal cost paths load balancing
More flexible than OSPF
Full support of distribute list
Manual summarization can be done in any
interface at any router within network
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E-IGRP PacketsE-IGRP Packets
Hello: Establish neighbor relationships
Update: Send routing updates
Query: Ask neighbors aboutrouting information
Reply: Response to query about
routing information
Ack: Acknowledgement of a reliable packet
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E-IGRP Neighbor RelationshipE-IGRP Neighbor Relationship
Two routers become neighbors when theysee each others hello packet
Hello address = 224.0.0.10
Hellos sent once every five seconds on
the following links:Broadcast Media: Ethernet, Token Ring,FDDI, etc.
Point-to-point serial links: PPP, HDLC, point-to-point frame relay/ATM subinterfaces
Multipoint circuits with bandwidth greater than
T1: ISDN PRI, SMDS, Frame Relay
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E-IGRP Neighbor RelationshipE-IGRP Neighbor Relationship
Hellos sent once every 60 seconds on the
following links:Multipoint circuits with bandwidth less than orequal to T1: ISDN BRI, Frame Relay, SMDS, etc.
Neighbor declared dead when no E-IGRPpackets are received within hold interval
Not only Hello can reset the hold timer
Hold time by default is three times thehello time
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E-IGRP Neighbor RelationshipE-IGRP Neighbor Relationship
E-IGRP will form neighbors even though
hello time and hold time dont match E-IGRP sources hello packets from
primary address of the interface
E-IGRP will not form neighbor if K-valuesare mismatched
E-IGRP will not form neighbor if ASnumbers are mismatched
Passive interface (IGRP vs. E-IGRP)
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Discovering RoutesDiscovering Routes
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
11Hello
AA BB
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Discovering RoutesDiscovering Routes
Update
afadjfjorqpoeru39547439070713
Here Is My Routing Information (Unicast) 22
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
11Hello
AA BB
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Discovering RoutesDiscovering Routes
Thanks for the Information!Ack
afadjfjorqpoeru39547439070713
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Update
afadjfjorqpoeru39547439070713
Here Is My Routing Information (Unicast) 22
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
11Hello
AA BB
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Topology
Table
TopologyTable
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Discovering RoutesDiscovering Routes
Thanks for the Information!Ack
afadjfjorqpoeru39547439070713
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Update
afadjfjorqpoeru39547439070713
Here Is My Routing Information (Unicast) 22
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
11Hello
AA BB
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Here Is My Route Information (Unicast)Update
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Topology
Table
TopologyTable
44 Thanks for the Information!Ack
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Update
afadjfjorqpoeru39547439070713
Here Is My Routing Information (Unicast) 22
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
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Discovering RoutesDiscovering Routes
Hello
AA BB
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Converged
Thanks for the Information!Ack
afadjfjorqpoeru39547439070713
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TopologyTable
TopologyTable
44
AA BB
Here Is My Route Information (Unicast)Update
afadjfjorqpoeru39547439070713
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Thanks for the Information!Ack
afadjfjorqpoeru39547439070713
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Update
afadjfjorqpoeru39547439070713
Here Is My Routing Information (Unicast) 22
I am Router A, Who Is on the Link?
afadjfjorqpoeru39547439070713
11Hello
Discovering RoutesDiscovering Routes
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AgendaAgenda
Fundamentals of E-IGRP DUAL
Summarization and Load Balancing
Query Process
Deployment Guidelines with E-IGRP
Summary
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E-IGRP DUALE-IGRP DUAL
Diffusing update algorithm
Finite-State-MachineTrack all routes advertised by neighbors
Select loop-free path using a successor andremember any feasible successors
If successor lost
Use feasible successor
If no feasible successor
Query neighbors and recompute new successor
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E-IGRP Feasible Distance (FD)E-IGRP Feasible Distance (FD)
Feasible distance is the minimum
distance (metric) along a path to adestination network
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TopologyTable
DestinationDestination Feasible Distance (FD)Feasible Distance (FD) NeighborNeighbor
77
77
77
HH
BB
DD
100+20+10=130100+20+10=130
100+1+10+10=121100+1+10+10=121
100+100+20+10+10=240100+100+20+10+10=240
Feasible Distance ExampleFeasible Distance Example
Network 7
FDDI
(10)(20)
(1) GG
CC
FFEE
BB
HH
DD
AA
(100)
(10)(20)(100)
(100)
(100)
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E-IGRP Reported Distance (RD)E-IGRP Reported Distance (RD)
Reported distance is the distance(metric) towards a destination as
advertised by an upstream neighborReported distance is the distance
reported in the queries, the replies andthe updates
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DestinationDestination Reported Distance (RD)Reported Distance (RD) NeighborNeighbor
77
77
77
20+10=3020+10=30
1+10+10=211+10+10=21
100+20+10+10=140100+20+10+10=140
HH
BB
DD
Topology
Table
Reported Distance ExampleReported Distance Example
FDDI
GG
CC
FFEE
Network 7
(10)(20)
(1)(100)
(10)(20)(100)
(100)
(100) BB
HH
DD
AA
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E-IGRP Feasibility Condition (FC)E-IGRP Feasibility Condition (FC)
A neighbor meets the feasibilitycondition (FC) if the reported
distance by the neighbor is smallerthan the feasible distance (FD) ofthis router
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E-IGRP SuccessorE-IGRP Successor
A successor is a neighbor that has metthe feasibility condition and has theleast cost path towards the destination
It is the next hop for forwarding packets
Multiple successors are possible(load balancing)
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E-IGRP Feasible Successor (FS)E-IGRP Feasible Successor (FS)
A feasible successor is a neighbor
whose reported distance (RD) is lessthan the feasible distance (FD)
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12112177 BB
Router AsRouting Table
Successor ExampleSuccessor Example
B is current successor (FD = 121)
H is the feasible successor (30 < 121)
DestinationDestination NeighborNeighbor
77
77
77
HH
BB
DD
TopologyTable
FDFD RDRD
3030130130
121121
240240
2121
140140
FDDI
GG
CC
FFEE
BB
HH
DD
AA
(20)(100)
Network 7
(10)(20)
(1)(100)
(10)
(100)
(100)
P i A i d S kP i A i d S k
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Passive, Active, and Stuckin Active (SIA)
Passive, Active, and Stuckin Active (SIA)
Passive routes are routes that havesuccessor information
Passive route = Good
Active routes are routes that have lost theirsuccessors and no feasible successors areavailable. The router is actively looking foralternative paths
Active route = Bad Stuck in Active means the neighbor still has not
replied to the original query within three minutes
Stuck in active = Ugly
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Dual AlgorithmDual Algorithm
Local computation
When a route is no longer available viathe current successor, the router checksits topology table
Router can switch from successor tofeasible successor without involving
other routers in the computationRouter stays passive
Updates are sent
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DUAL: Local Computation
(1)
#2
#3
#4 #5
B C
FD E
#1
#6
GA
#7
(100)
(100) (20)
(10)
(10)
(10)
H
#8(20)
#7 121/21 B
#7 130/30 H
. . .
. . .
. . .
#7 121/21 B
#7 130/30 H
. . .
. . .
. . .
FDDI
XX
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Dual AlgorithmDual Algorithm
Diffused Computation
When a route is no longer available via its
current successor and no feasible successor isavailable, queries are sent out to neighborsasking about the lost route
The route is said to be in active state
Neighbors reply to the query if they haveinformation about the lost route. If not, queriesare sent out to all of their neighbors.
The router sending out the query waits for all ofthe replies from its neighbors and will makerouting decision based on the replies
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(1)
#2
#3
#4 #5
B C
FD E
#1
#6
GA
#7
(100)
(100) (20)
(10)
(10)
(10)
H
#8(20)
#7 121/21 B
#7 130/30 H
. . .
. . .
. . .
#7 121/21 B
#7 130/30 H
. . .
. . .
. . .
FDDI
XX
DUAL: Diffused Computation
XX
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D E-IGRP Topology(a) Cost (2) (fd)
via B Cost (2/1) (Successor)via C Cost (5/3)
D E-IGRP Topology(a) Cost (2) (fd)
via B Cost (2/1) (Successor)via C Cost (5/3)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via D Cost (4/2) (fs)via E Cost (4/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via D Cost (4/2) (fs)via E Cost (4/3)
(1)
DUAL ExampleDUAL Example
XXX
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
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D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3) (q)
D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3) (q)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E Cost (4/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E Cost (4/3)
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
DUAL ExampleDUAL Example
QQQQQQ
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D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3)
D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3)
E E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via D
via C Cost (4/3) (q)
E E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via D
via C Cost (4/3) (q)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
DUAL ExampleDUAL Example
RRR
QQQ
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
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D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3)
D E-IGRP Topology(a) **ACTIVE** Cost (-1) (fd)
via E (q)via C Cost (5/3)
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
DUAL ExampleDUAL Example
RRR
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
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D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
DUAL ExampleDUAL Example
RRR
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
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D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
DUAL ExampleDUAL Example
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
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(1)
(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
E E-IGRP Topology(a) Cost (3) (fd)
via D Cost (3/2) (Successor)
via C Cost (4/3)
D E-IGRP Topology(a) Cost (2) (fd)
via B Cost (2/1) (Successor)via C Cost (5/3)
D E-IGRP Topology(a) Cost (2) (fd)
via B Cost (2/1) (Successor)via C Cost (5/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via D Cost (4/2) (fs)via E Cost (4/3)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via D Cost (4/2) (fs)via E Cost (4/3)
DUAL Example (Start)DUAL Example (Start)
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(1)
(1)
(1)
(2)(2)
A
D
EC
B
(a)
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
E E-IGRP Topology(a) Cost (4) (fd)
via C Cost (4/3) (Successor)
via D
D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
D E-IGRP Topology(a) Cost (5) (fd)
via C Cost (5/3) (Successor)via E Cost (5/4) (Successor)
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
C E-IGRP Topology(a) Cost (3) (fd)
via B Cost (3/1) (Successor)via Dvia E
DUAL Example (End)DUAL Example (End)
E IGRP ReliableE IGRP Reliable
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E-IGRP ReliableTransport Protocol
E-IGRP ReliableTransport Protocol
E-IGRP reliable packets are packets thatrequires explicit acknowledgement:
Update
Query
Reply
E-IGRP unreliable packets are packets that
do not require explicit acknowledgement:
Hello
Ack
E IGRP ReliableE IGRP Reliable
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E-IGRP ReliableTransport Protocol
E-IGRP ReliableTransport Protocol
The router keeps a neighbor list and aretransmission list for every neighbor
Each reliable packet (Update, Query,Reply) will be retransmitted when packet
is not acked
E-IGRP transport has window size of one
(stop and wait mechanism)Every single reliable packet needs to beacknowledged before the next sequenced
packet can be sent
E IGRP ReliableE IGRP Reliable
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E-IGRP ReliableTransport Protocol
E-IGRP ReliableTransport Protocol
With reliable multicast traffic, one mustwait to transmit the next reliable multicastpackets, until all peers haveacknowledged the previous multicast
If one or more peers are slow inacknowledging, all other peers sufferfrom this
Solution: The nonacknowledged multicastpacket will be retransmitted as a unicast to
the slow neighbor
E IGRP ReliableE IGRP Reliable
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E-IGRP ReliableTransport Protocol
E-IGRP ReliableTransport Protocol
Per neighbor, retransmission limit
is 16 Neighbor relationship is reset when
retry limit (limit = 16) for reliablepackets is reached
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AgendaAgenda
Fundamentals of E-IGRP DUAL
Summarization and Load Balancing
Query Process
Deployment Guidelines with E-IGRP
Summary
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E-IGRP SummarizationE-IGRP Summarization
Purpose: Smaller routing tables, smallerupdates, query boundary
Auto summarization:
On major network boundaries, networks are
summarized to the major networks
Auto summarization is turned on by default
192.168.1.x
192.168.1.0
192.168.2.x
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E-IGRP SummarizationE-IGRP Summarization
Manual summarization
Configurable on per interface basis in anyrouter within network
When summarization is configured on an interface, therouter immediate creates a route pointing to null zerowith administrative distance of five
Loop prevention mechanism
When the last specific route of the summary goes away,the summary is deleted
The minimum metric of the specific routes is used asthe metric of the summary route
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192.168.9.X
192.168.10.X
192.168.8.0/22
interface s0ip address 192.168.11.1 255.255.255.252ip summary-address E-IGRP 1 192.168.8.0 255.255.252.0
S0
AS 1
E-IGRP SummarizationE-IGRP Summarization
Manual summarization command:
ip summary-address E-IGRP
192.168.8.X
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E-IGRP Load BalancingE-IGRP Load Balancing
Routes with equal metric to the
minimum metric, will be installed inthe routing table (Equal Cost LoadBalancing)
There can be up to six entries in the
routing table for the same destination(default = 4)
ip maximum-paths
E-IGRP UnequalE-IGRP Unequal
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E-IGRP UnequalCost Load Balancing
E-IGRP UnequalCost Load Balancing
E-IGRP offers unequal cost load
balancing feature with the command:Variance
Variance command will allow the routerto include routes with a metric smallerthan multiplier times the minimum
metric route for that destination, wheremultiplier is the number specified by
the variance command
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10
20
10
10
20
25
A
B
C
D
E
Variance 2
Variance ExampleVariance Example
Router E will choose router C to get tonet X FD=20
With variance of 2, router E will also chooserouter B to get to net X
Router D will not be used to get to net X
Net X
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AgendaAgenda
Fundamentals of E-IGRP DUAL
Summarization and Load Balancing
Query Process
Deployment Guidelines with E-IGRP
Summary
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Have You Seen My Sparky?
E-IGRP Query ProcessE-IGRP Query Process
E-IGRP is Advanced
Distant Vector. It relies onits neighbor to providerouting information
If a route is lost and nofeasible successor isavailable, E-IGRP needs toconverge fast, its only
mechanism for fastconvergence is to activelyquery for the lost route toits neighbors
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E-IGRP Query ProcessE-IGRP Query Process
Queries are sent out when a route is lost
and no feasible successor is available The lost route is now in active state
Queries are sent out to all of its neighborson all interfaces except the interface tothe successor
If the neighbor does not have the lostroute information, queries are sent out to
their neighbors
E IGRP Q P
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E-IGRP Query ProcessE-IGRP Query Process
The router will have to get ALL of the
replies from the neighbors before the routercalculates the successor information
If any neighbor fails to reply the query inthree minutes, this route is stuck in activeand the router resets the neighbor that fails
to reply Solution is to limit query range to be
covered later in presentation
G QE IGRP Q R
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A
AS 1AS 2
C
Network X
Query for XQuery for XReply for XReply for XQuery for XQuery for X
E-IGRP Query RangeE-IGRP Query Range
Autonomous System Boundaries
Contrary to popular belief, queries are notbounded by AS boundaries. Queries from AS 1will be propagated to AS 2
B
XX
E IGRP Q RE IGRP Q R
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A CB130.130.1.0/24
B Summarizes 130.0.0.0/8 to A
130.x.x.x
Reply with Infinity and theQuery Stops Here!
Query for130.130.1.0/24
E-IGRP Query RangeE-IGRP Query Range
Summarization point
Auto or manual summarization bound queriesRequires a good address allocation scheme
XX129.x.x.x
Query for130.130.1.0/24
E IGRP B d id h U ili iE IGRP B d idth Utili ti
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E-IGRP Bandwidth UtilizationE-IGRP Bandwidth Utilization
E-IGRP by default will use up to 50%
of the link bandwidth forE-IGRP packets
This parameter is manuallyconfigurable by using the command:
ip bandwidth-percent E-IGRP
Use for greater E-IGRP load control
B d id h WAN I fB d idth WAN I t f
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Bandwidth over WAN InterfacesBandwidth over WAN Interfaces
Bandwidth utilization over point-to-point subinterface Frame Relay
Treats bandwidth as T1 by default
Best practice is to manually configurebandwidth as the CIR of the PVC
B d idth WAN I t fB d idth WAN I t f
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Bandwidth over WAN InterfacesBandwidth over WAN Interfaces
Bandwidth over multipoint Frame Relay,ATM, SMDS, and ISDN PRI:
E-IGRP uses the bandwidth on the maininterface divided by the number of neighborson that interface to get the bandwidth
information per neighbor
B d idth WAN I t fB d idth WAN I t f
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Bandwidth over WAN InterfacesBandwidth over WAN Interfaces
Each PVC might have different CIR, this
might create E-IGRP packet pacing problemMultipoint interfaces:
Convert to point-to-pointBandwidth configured = (lowest CIR x numberof PVC)
ISDN PRI:
Use Dialer Profile (treat as point-to-point link)
A dA d
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AgendaAgenda
Fundamentals of E-IGRP DUAL
Summarization and Load Balancing
Query Process
Deployment Guidelines with E-IGRP
Summary
Factors That InfluenceFactors That Influence
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Factors That InfluenceE-IGRP Scalability
Factors That InfluenceE-IGRP Scalability
Keep in mind that E-IGRP is not plugand play for large networks
Limit E-IGRP query range!
Quantity of routing informationexchanged between peers
Limiting Updates/QueriesLimiting Updates/Queries
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10.1.8.0/24
RTRB
RTRA
RTRC
RTRD
RTRE
Distribution Layer Remote Sites
Limiting Updates/QueriesExample
Limiting Updates/QueriesExample
Limiting Size/Scope ofLimiting Size/Scope of
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Limiting Size/Scope ofUpdates/Queries
t g S e/Scope oUpdates/Queries
Evaluate routing requirements
What routes are needed where?
Once needs are determinedUse summary address
Use new E-IGRP Stub feature(To be discussed later)
Use distribute lists
Limiting Updates/Q eries E ampleLimiting Updates/Queries Example
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RTRB
RTRA
RTRC
RTRD
RTRE
Distribution Layer Remote Sites
XQueriesQueriesRepliesReplies
Limiting Updates/QueriesExampleLimiting Updates/QueriesExample
Limiting Updates/Queries SummaryLimiting Updates/Queries Summary
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Limiting Updates/QueriesSummaryLimiting Updates/QueriesSummary
Remote routers fully involvedin convergence
Most remotes are never intendedto be transit
Convergence complicated throughlack of information hiding
Limiting Updates/Queries BetterLimiting Updates/Queries Better
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10.1.8.0/24
RTRB
RTRA
RTRC
RTRD
RTRE
Distribution Layer Remote Sites
XQueriesQueriesRepliesReplies
IP summary-address E-IGRP 1 10.0.0.0 255.0.0.0on all outbound interfaces to remotes
Limiting Updates/QueriesBetterLimiting Updates/QueriesBetter
Limiting Updates/Queries SummaryLimiting Updates/Queries Summary
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Limiting Updates/Queries SummaryLimiting Updates/Queries Summary
Convergence simplified by addingthe summary-address statements
Remote routers just reply
when queried
Limiting Updates/QueriesLimiting Updates/Queries
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g pNew Featureg pNew Feature
New E-IGRP STUB command is now
available (12.0.7T and higher)
[no] E-IGRP stub [receive-only]
[connected] [static] [summary]
Only specified routes are advertised.
Any neighbor receiving stubinformation from a neighbor will not
query those routers for any routes
Limiting Updates/Queries BestLimiting Updates/Queries Best
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Limiting Updates/QueriesBestLimiting Updates/QueriesBest
Best practice is to combineSummarization and E-IGRP STUBcommand
Limiting Updates/Queries BestLimiting Updates/Queries Best
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RTRB
RTRA
RTRC
RTRD
RTRE
Distribution Layer Remote Sites
XQueriesQueries
RepliesReplies
IP summary-address E-IGRP 1 10.0.0.0 255.0.0.0 E-IGRP stub connectedon all outbound interfaces to remotes on all remote routers C, D, and E
Limiting Updates/QueriesBestLimiting Updates/QueriesBest
Hierarchy/AddressingHierarchy/Addressing
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Hierarchy/AddressingHierarchy/Addressing
Permits maximum information hiding
Advertise major net or default routeto regions or remotes
Provides adequate redundancy
E IGRP ScalabilityE IGRP Scalability
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E-IGRP ScalabilityE-IGRP Scalability
E-IGRP is a very scalable routing
protocol if proper design methodsare used:
Good allocation of address space
Each region should have an uniqueaddress space so route summarization
is possibleHave a tiered network design model(Core, Distribution, Access)
E IGRP ScalabilityE IGRP Scalability
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E-IGRP ScalabilityE-IGRP Scalability
Use of E-IGRP Stub command if possible
Proper network resources
Sufficient memory on the router
Sufficient bandwidth on WAN interfaces
Proper configuration of the bandwidthstatement over WAN interfaces, especially
over Frame Relay Avoid blind mutual redistribution between
two routing protocols or two E-IGRP processes
Tiered Network DesignTiered Network Design
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DistributionLayer
Access Layer
Summarized RoutesSummarized Routes
Summarized RoutesSummarized RoutesSummarized RoutesSummarized Routes
Summarized RoutesSummarized Routes
Summarized RoutesPossible stub
Summarized RoutesPossible stub
Summarized RoutesPossible Stub
Summarized RoutesPossible Stub
Tiered Network DesignTiered Network Design
OtherRegions
OtherRegions
OtherRegions
OtherRegions
Core
Nonscalable NetworkNonscalable Network
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Core
TokenRing
TokenRing
3.3.4.01.1.1.0
3.3.4.0
1.1.4.0
3.3.3.0
2.2.1.0
1.1.3.0
3.3.1.0
1.1.2.02.2.3.0
2.2.2.0
TokenRing
TokenRing
TokenRing
TokenRing
1.1.1.0
1.1.2.02.2.3.03.3.4.0
2.2.1.0
3.3.2.03.3.3.01.1.4.0
3.3.1.02.2.2.01.1.3.0
Nonscalable NetworkNonscalable Network
Bad addressing scheme
Subnets are everywhere throughout entire network Queries not bounded
Scalable NetworkScalable Network
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Core
3.0.0.0
2.0.0.0
TokenRing
TokenRing
1.1.4.01.1.1.0
3.3.4.0
3.3.4.0
3.3.3.0
3.3.1.0
2.2.3.0
2.2.1.0
1.1.2.01.1.3.0
2.2.2.0
1.0.0.0
TokenRing
TokenRing
TokenRing
TokenRing
Scalable NetworkScalable Network
Readdress networkEach region has its own block of address
Queries bounded by using ip summary-address E-IGRP command
SummarySummary
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SummarySummary
Query range
Best way to limit query is through route summarization
and new E-IGRP Stub command
E-IGRP is not plug and play for large networks
Its a very scalable protocol with little design requirement
Optimizing E-IGRP network
Limiting query range
Route summarizationTiered network design
Use of E-IGRP Stub command
Sufficient network resources
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Deploying IGRP/E-IGRPDeploying IGRP/E-IGRP
Session 2208Session 2208
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Please Complete Your
Evaluation Form
Please Complete Your
Evaluation FormSession 2208Session 2208
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