Review Questions


1.

What components or mechanisms of a link state protocol can an attacker target?

2.

In what way does the fact that IS-IS is not itself an IP protocol give it a security advantage over OSPF?

3.

What is "fightback" behavior?

4.

Why is simple password authentication less desirable that MD5 authentication?

5.

What is a message digest, and how does it protect the keys used for authentication?

6.

What is the benefit of the OSPF Key ID?

7.

What is the purpose of the OSPF cryptographic sequence number in MD5 authentication?

8.

In what way is IS-IS more vulnerable to replay attack than OSPF?

9.

What three authentication scopes are defined for IS-IS? How do the three scopes differ in regard to the carrying of the Authentication Information TLV?

10.

How does the enabling of MD5 authentication change the checksum procedures of OSPF and IS-IS?

11.

What is graceful restart? What feature of many modern high-end routers makes graceful restart possible?

12.

What LSA does OSPF use to support graceful restart?

13.

What is the purpose of the restart period?

14.

What is a graceful restart helper?

15.

What is the difference between a planned and an unplanned restart?

16.

What is the purpose of the RR and RA flags in the IS-IS Restart TLV?

17.

What is the purpose of the SA flag in the IS-IS Restart TLV?

18.

What determines the value of the remaining time field in the IS-IS Restart TLV?

19.

What is bidirectional forwarding detection? How does it improve on the Hello mechanisms of routing protocols?




OSPF and IS-IS(c) Choosing an IGP for Large-Scale Networks
OSPF and IS-IS: Choosing an IGP for Large-Scale Networks: Choosing an IGP for Large-Scale Networks
ISBN: 0321168798
EAN: 2147483647
Year: 2006
Pages: 111
Authors: Jeff Doyle

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