Ccna3 Chapter 7

Front 1

EIGRP was initially released in

Back 1

1992 as a proprietary protocol.

Front 2

EIGRP includes features of both

Back 2

link-state and distance vector routing protocols.

Front 3

EIGRP is still based on the key

Back 3

distance vector routing protocol principle.

Front 4

The key distance vector routing protocol principle

Back 4

information about the rest of the network is learned from directly connected neighbors.

Front 5

Diffusing Update Algorithm (DUAL)

Back 5

DUAL guarantees loop-free and backup paths throughout the routing domain.

Front 6

Using DUAL, EIGRP stores all available backup routes for destinations so that it can

Back 6

quickly adapt to alternate routes when necessary.

Front 7

Partial Updates

Back 7

the update only includes information about the route changes.

Front 8

Bounded Updates

Back 8

the propagation of partial updates that are sent only to those routers that the changes affect.

Front 9

EIGRP Supports:

Back 9

equal cost load balancing

unequal cost load balancing

Front 10

EIGRP has the capability for routing several different protocols using

Back 10

protocol-dependent modules (PDMs).

Front 11

PDMs are responsible for 1:

Back 11

Maintaining the neighbor and topology tables.

Front 12

PDMs are responsible for 2:

Back 12

Building and translating protocol-specific packets for DUAL

Front 13

PDMs are responsible for 3:

Back 13

Interfacing DUAL to the protocol-specific routing table

Front 14

PDMs are responsible for 4:

Back 14

Computing the metric and passing this information to DUAL

Front 15

PDMs are responsible for 5:

Back 15

Implementing filtering and access lists

Front 16

PDMs are responsible for 6:

Back 16

Performing redistribution functions to and from other routing protocols

Front 17

PDMs are responsible for 7:

Back 17

Redistributing routes that are learned by other routing protocols

Front 18

When a router discovers a new neighbor, it records the neighbor’s

Back 18

address and interface as an entry in the neighbor table.

Front 19

EIGRP also maintains a topology table. The topology table contains all destinations that are

Back 19

advertised by neighboring routers.

Front 20

There is also a separate topology table for each

Back 20

PDM.

Front 21

The Reliable Transport Protocol (RTP) is unique to EIGRP and provides delivery of

Back 21

EIGRP packets to neighbors.

Front 22

RTP includes both:

Back 22

reliable delivery

unreliable delivery

Front 23

Reliable RTP requires an

Back 23

acknowledgment.

Front 24

An unreliable RTP packet does not require an

Back 24

acknowledgment.

Front 25

RTP can send EIGRP packets as

Back 25

as unicast or multicast.

Front 26

Multicast EIGRP packets for IPv4 use the reserved IPv4 multicast address

Back 26

224.0.0.10.

Front 27

Multicast EIGRP packets for IPv6 are sent to the reserved IPv6 multicast sent to the reserved IPv6 multicast address

Back 27

FF02::A.

Front 28

Authentication does not encrypt theEIGRP

Back 28

routing updates.

Front 29

EIGRP Packet Types:

Back 29

Hello packets

Update packets

Acknowledgment packets

Query packets

Reply packets

Front 30

Hello packets

Back 30

Used for neighbor discovery

maintain neighbor adjacencies

sent as multicast packets every five seconds.

Unreliable, multicast.

Front 31

Update packets

Back 31

Propagates routing information

sent as a multicast or unicast

Reliable, multi/unicast

Front 32

Acknowledgment packets

Back 32

acknowledge the receipt of an EIGRP message.

Unreliable, unicast.

Front 33

Query packets

Back 33

Used to query routes from neighbors.

Reliable, multi/unicast.

Front 34

Reply packets

Back 34

Sent in response to an EIGRP query.

Reliable, unicast.

Front 35

EIGRP uses a Hold timer to determine the maximum time the router should wait to

Back 35

receive the next Hello before declaring that neighbor as unreachable.

Front 36

By default, the hold time is three times the Hello interval,

Back 36

or 15 seconds.

Front 37

If the hold time expires, EIGRP declares the route as

Back 37

down.

Front 38

The autonomous system number used for EIGRP configuration is only significant to the

Back 38

EIGRP routing domain

Front 39

The autonomous system number functions as a process ID to help routers keep track of multiple, running

Back 39

instances of EIGRP.

Front 40

The EIGRP router ID is used to uniquely identify each router in the

Back 40

the EIGRP routing domain.

Front 41

Determining the router-ID:

Back 41

Router-id > loopback > Highest IPv4 address

Front 42

The use of Passive-interfaces:

Back 42

To suppress unnecessary update traffic

To increase security controls

Front 43

Show ip eigrp neighbors: H

Back 43

Lists the neighbors in the order that they were learned.

Front 44

Show ip eigrp neighbors: Address

Back 44

IPv4 address of the neighbor.

Front 45

Show ip eigrp neighbors: Interface

Back 45

Local interface on which this Hello packet was received.

Front 46

Show ip eigrp neighbors: Hold

Back 46

Current hold time.

Front 47

Show ip eigrp neighbors: Uptime

Back 47

Amount of time since this neighbor was added to the neighbor table.

Front 48

Routing Update Sequence:

Back 48

R1: Hello

R2: Update

R2: Hello

R1: Ack

R1: Update

R2: Ack

Front 49

The metric calculation method (k values) and the EIGRP autonomous system number must match between EIGRP

Back 49

neighbors.

Front 50

EIGRP uses the bandwidth and delay as a metric to calculate the

Back 50

preferred path to a network.

Front 51

Most serial interfaces use the default bandwidth value of

Back 51

1544 kb/s.

Front 52

Modifying the bandwidth value does not change the

Back 52

actual bandwidth of the link.

Front 53

The bandwidth command only modifies the

Back 53

bandwidth metric.

Front 54

delay is the cumulative (sum) of all interface delays

Back 54

along the path.

Front 55

The decision process for all route computations is done by the

Back 55

DUAL Finite State Machine (FSM).

Front 56

The DUAL FSM:

Back 56

tracks all routes

uses EIGRP metrics to select efficient.

loop-free paths.

identifies the routes with the least-cost path to be inserted into the routing table.

Front 57

A successor is a neighboring router that is used for

Back 57

packet forwarding

Front 58

A successor is a neighboring router that is the

Back 58

least-cost route to the destination network.

Front 59

The IP address of a successor is shown in a routing table entry right after the word

Back 59

via.

Front 60

FD is the lowest calculated metric to reach the

Back 60

destination network.

Front 61

DUAL backup paths are known as

Back 61

Feasible Successors (FSs).

Front 62

A FS is a neighbor that has a loop-free backup path to the same network as the successor, and it satisfies the

Back 62

Feasibility Condition.

Front 63

The FC is met when a neighbor’s Reported Distance (RD) to a network is

Back 63

less than the local router’s feasible distance.

Front 64

If there are not any FSs in the topology table, DUAL puts the network into the

Back 64

active state.