Module 1

Question 1

What does OSPF mean

Answer 1

Open Shortest Path First

Question 2

A link-state routing protocol that was developed as an alternative for the distance vector Routing Information Protocol (RIP)

Answer 2

OSPF

Question 3

an interface on a router, a network segment that connects two routers, or a stub network such as an Ethernet LAN that is connected to a single router

Answer 3

link

Question 4

What are the five types of OSPF Packets?

Answer 4

• Hello packet
• Database description packet
• Link-state request packet
• Link-state update packet
• Link-state acknowledgment packet

Question 5

OSPF database which lists of all neighbor routers to which a router has established bi-directional communication

Answer 5

Adjacency Database

Question 6

OSPF database which lists information about all other routers in the network.

Answer 6

Link-state Database (LSDB)

Question 7

OSPF database which lists the routes generated when an algorithm is run on the link-state database

Answer 7

Forwarding Database

Question 8

5 link-state routing steps that are completed by a router

Answer 8

1. Establish Neighbor Adjacencies
2. Exchange Link-State Advertisements
3. Build the Link State Database
4. Execute the SPF Algorithm
5. Choose the Best Route

Question 9

OSPF implementation where all routers are in one area

Answer 9

Single-Area OSPF

Question 10

OSPF implementation where OSPF is implemented using multiple areas, in a hierarchical fashion. All areas must connect to the backbone area (area 0)

Answer 10

Multiarea OSPF

Question 11

Routers interconnecting the areas are referred to as ____

Answer 11

Area Border Routers (ABRs)

Question 12

OSPF packet which discovers neighbors and builds adjacencies between them

Answer 12

Hello Packet

Question 13

OSPF packet which checks for database synchronization between routers

Answer 13

Database Description (DBD)

Question 14

OSPF packet which requests specific link-state records from router to router

Answer 14

Link-State Request (LSR)

Question 15

OSPF packet which sends specifically requested link-state records

Answer 15

Link-State Update (LSU)

Question 16

OSPF packet which acknowledges the other packet types

Answer 16

Link-State Acknowledgment (LSAck)

Question 17

What are the 7 states of OSPF operation?

Answer 17

• Down state
• Init state
• Two-way state
• ExStart state
• Exchange state
• Loading state
• Full state

Question 18

Operational State where no Hello packets are received; therefore the router sends Hello packets

Answer 18

Down State

Question 19

Operational State where Hello packets are received from the neighbor containing the Router ID of the sending router

Answer 19

Init State

Question 20

Operational State that communicates between the two routers

Answer 20

Two-way State

Question 21

Operational State where the two routers seen in point-to-point networks decide which router will initiate the DBD packet exchange and decide upon the initial DBD packet sequence number

Answer 21

ExStart State

Question 22

Operational State where routers exchange DBD packets

Answer 22

Exchange State

Question 23

Operational State where LSRs and LSUs are used to gain additional route information.

Answer 23

Loading State

Question 24

Operational State wherein the link-state database of the router is fully synchronized

Answer 24

Full State

Question 25

A router that is neither the DR nor the BDR.

Answer 25

DROTHER