Ccnp Route, Chapter 11,12,14

Front 1

Where do we have to configure OSPF summarization

Back 1

ABR or ASBR

NOTE:
OSPF can only summarize our LSA type 3 and 5

Front 2

What does summarization of type 3 LSA mean?

Back 2

It means we are creating a summary of all the interarea routes.

NOTE:
This is why we call it interarea route summarization

Front 3

When will a summary route be advertised?

Back 3

If it has at least one subnet that falls within the summary range

Front 4

A summary route will have ______________

Back 4

the cost of the subnet with the lowest cost that falls within the summary range

Front 5

What kind of interface does the ABR summary route create?

Back 5

null0 interface

NOTE:

This is done to prevent loops

Front 6

What does the

area range

command do?

Back 6

We can summarize the type 3 summary LSA

Front 7

What is external route summarization?

Back 7

This is where we summarize the type 5 external LSAs

Front 8

Type 5 external LSA show up as _________ in the routing table

Back 8

O E2

Front 9

What command do you use to summarize the type 5 external LSAs

Back 9

Summary-Address

command

Front 10

What does the default-information originate command do

Back 10

You can advertise a default route if you don't already have it in your routing table

Front 11

What happens if you add always to the end of default-information originate command

Back 11

default-information originate always

It will advertise the default route even if you don't have it in the routing table

Front 12

What are the special area types in OSPF?

Back 12

• Stub area
• Totally Stubby Area
• NSSA (not so stubby area)
• Totally NSSA (totally not so stubby area)

Front 13

What happens when you configure an area as a stub?

Back 13

It will block all type 5 external LSAs

NOTE:
All the prefixes that you redistribute into OSPF from another routing protocol are not welcome in the stub area.

Front 14

Why is it impossible to have an ASBR in the stub area?

Back 14

You are not allowed to have type 5 external LSA in a stub area. An ASBR requires type 5 LSA.

Front 15

What happens if you want an area to be a stub area but you have an ASBR in the area?

Back 15

You can use the NSSA (not-so-stubby area)

NOTE:
This is the same thing as the stub area with the exception that you are allowed to have an ASBR within the area

Front 16

In an NSSA what type of LSA do we use?

Back 16

Not-so-stubby-area

We use type 7 external LSA

Front 17

What type of LSA does a totally stub block?

Back 17

type 5 external LSAs

and

Type 3 summary LSAs

Front 18

What router cannot be in a totally stub area?

Back 18

ASBR - Autonomous System Boundary Routers

NOTE:

ASBR requires type 5 LSAs

Front 19

If you want to block type 3 summary LSAs and type 5 external LSAs but still need an ASBR within the totally stub area. What type of area can you turn it into?

Back 19

totally NSSA - totally not-so-stubby-area

NOTE:

This will block both type 3 and 5 but you can still have an ASBR in this area type

Front 20

4 common rules to a stub and totally stub areas

Back 20

1. There should be at least one ABR in the area
2. All routers in the stub area have to be configured as a stub router
3. There is no ASBR within the stub or totally stub area
4. The Backbone area cannot become stub or totally stub area

Front 21

What is the command to turn ospf into a stub?

Back 21

router(config)#router ospf 1

router(config-router)#area 1 stub

Front 22

What types of authentication can OSPF use?

Back 22

• Plaintext
• MD5

Front 23

What is the command to enable OSPF authentication?

Back 23

router(config)#router ospf 1
router(config-router)#ip ospf authentication
router(config-router)#ip ospf authentication-key cisco(or whatever)

Front 24

The ip ospf authentication command enables __________ ?

Back 24

plain text authentication

Front 25

At what level is the does the ip ospf authentication command enable this form of authentication?

Back 25

interface

Front 26

What can you see with the show ip ospf command?

Back 26

• ospf information per interface
• check if authentication is enabled
• neighbor count
• check if simple password authentication is enabled

Front 27

Other than show ip ospf what command can you used to verify authentication is enabled?

Back 27

debug ip ospf packet

Front 28

What are the codes for authentication show with a debug ip ospf packet?

Back 28

• Aut:0
• Aut:1
• Aut:2

Front 29

What Aut:0?

Back 29

no authentication

Front 30

What is Aut:1

Back 30

plaintext Authentication

Front 31

What is Aut:2

Back 31

MD5 authentication

Front 32

How do you enable MD5 authentication?

Back 32

router(config)# int fa 0/0

router(config-if)#ip ospf message-digest-key 1 md5 cisco(or whatever)

router(config-if)#ip ospf authentication message-digest

Front 33

what is does the command

ip ospf message-digest-key md5

mean?

Back 33

This is used for MD5 to specify the key number and a password.

NOTE:

The key # must be the same on both ends

Front 34

To enable ospf authentication, what is the command

Back 34

ip ospf authentication message-digest

Front 35

What is the command to create a virtual link

Back 35

router(config)#router ospf 1

router(config-router)#area 1 virtual-link 192.1.1.1

Front 36

What command do you use to check if your virtual link is working

Back 36

show ip ospf virtual-links

Front 37

What does DNA mean?

Back 37

Do Not Age