chapter 7 part 3

Question 1

ipv6 EIGRP multicast address is?

Answer 1

The reserved EIGRP multicast address for IPv6 is FF02::A.

Question 2

The reserved EIGRP multicast address for IPv4 is ?

Answer 2

224.0.0.10.

Question 3

how long is the default hold time (waiting for a hello packet)?

Answer 3

3 times the hello interval. so 15 seconds or if using NBMA non-broadcast multiple access its more like 180 seconds because these are lower speed connections.

Question 4

what is the multicast mac address?

Answer 4

01-00-5E-xx-xx-xx

Question 5

what is TLV?

Answer 5

time length value: the data field portion of a EIGRP packet.

Question 6

what is the autonomous system number?

Answer 6

a number that is used by each EIGRP packet to distinguish itself from other unrelated proccesses that are also using EIGRP to have their own conversations. (allows many conversations to be had at the same time using EIGRP).**All routers within the EIGRP routing domain must use the same autonomous system number

Question 7

what command is used to gain access to the EIGRP settings on a router?

Answer 7

# router eigrp 'autonomous system number'
**to make EIGRP active on the router one must: configure it.

Question 8

the command does what?…: #router ?

Answer 8

lists all the avilable routing protocols on that router such as… eigrp, ospf, etc.

Question 9

how is the eigrp router id derived? what crterial is there?

Answer 9

1- the router command is used with a ipv4 address #eigrp router-id ‘ipv4 number’
2- highest ipv4 loopback chosen
3- highest active ipv4 address chosen
*the interface does not need to be enabled for eigrp but must be up/up

Question 10

what command is used to set an interface as passive?

Answer 10

#router eigrp 'number'
#passive-interface "interface"

Question 11

what are the administrative distances of eigrp? for default AD, internal route, external source routes and summary AD routes?

Answer 11

AD internal = 90
AD external source = 170
AD summary = 5

Question 12

routing table letter D means what?

Answer 12

EIGRP is used D is used b/c DUAL algorithm is used in eigrp.

Question 13

what does BW mean when in the #show interfaces

output?

Answer 13

bandwidth and this is measured in kib/sec.

Question 14

what command is used to change the bandwidth on an interface so that it gets chosen in a particular order over other interfaces when using internet protocols (ip eigrp/ospf)?

Answer 14

(config-interface)#bandwidth ‘bandwidth-number’

remember to exit after entering each interface bandwidth number.

Question 15

what is DUAL?

Answer 15

Diffusing update protocol: used by eigrp as an algorith to calculate a loop-free path.

Question 16

what is FSM?

Answer 16

Finite State Machine (FSM): The DUAL FSM tracks all routes, uses EIGRP metrics to select efficient, loop-free paths, and identify the routes with the least-cost path to be inserted into the routing table.

Question 17

what is a successor?

Answer 17

displayed in a route table entry after the word ‘via’ (neighbor router used for packet forwarding).

Question 18

Feasible Successors (FS)?

Answer 18

a backup route/ router used when the successor (main router route to destination) is down.

Question 19

what is a FC?

Answer 19

feasibility condition. when the feasible successor is chosen by checking other router connections to the destination and making sure that the other routers reported distance (RD) is less than the sending routers distance.

Question 20

RD is what?

Answer 20

reported distance: the metric in distance/cost from the sending router to the destination network via the next hop routers.

Question 21

FD?

Answer 21

feasible distance: the cost in the route table displaying the cost to get to destination network.

Question 22

what does the following command do? #debug eigrp fsm

Answer 22

is used to show what the DUAL algorithm does when a route is removed from the routing table. (FSM) finite state machine: this is DUAL algorithm.