ITM 280 - Chapter 8 Review

4. In routers ports are called _?_ (305)

*Interfaces*

30. Identify two header types designed to implement security in IPv6. (328-329)

*authentication header* and the *encapsulating security payload (ESP) field*

17. Given an IP address and a routing table be able to determine which Interface to send an IP out on. (314-318 and notes)

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19. What are the two metrics used in routing? (316)

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27. Know, in general, the purpose of the fields within the header of an IPv6 packet. (325-328)

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28. The protocol field of IPv4 has been replaced by which field in IPv6? (328)

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29. Suppose an IPv6 packet had the value 6 in its Next Header field. This would indicate that the data in the packet was what sort of payload? (328-329)

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33. How does TCP achieve reliability. Be specific. (331-332)

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35. What is the purpose of the port fields? (notes)

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36. What is the difference between a well-known port and an ephemeral port number? (notes)

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37. Know the well-known port numbers for HTTP and SMTP (notes or look it up)

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38. Suppose I am using a browser and send a request for a web page. What will the destination port number be? What sort of address will be used in the source port number? (notes)

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39. A combination of a port number and an IP address such as 227.68.22.210:80 is called a _?_ (notes)

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40. Distinguish between UDP and TCP in terms of: a. Segmentation (333) b. Reliability (notes & chapter 2)

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41. How does a router get the information it needs to fill a routing table? (334)

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42. Know the major routing protocols. Which ones are used for internal routing? Which one is used for exterior routing? How are the Interior protocols different from each other? (334-336)

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34. Identify three uses of the Flag field. (332)

1. ACK (acknowledgement) 2. SYN (synchronization) 3. FIN (finish)

24. Know, in general the purpose of each field in an IPv4 packet. (320-322)

1. IP Time to Live (TTL) Field - given a value by the source host 2. IP Protocol Field - content of the data field 3. IP Identification, Flags, and Fragment Offset Fields 4. IP Options 5. IP Diff-Serv

2. Know the five layers of the TCP/IP / OSI protocol. Know which ones are OSI standards. (Fig. 8-1)

5. Application (none) 4. Transport (OSI) 3. Internet (OSI) (PG 304)

15. Be able to use a mask to separate the host portion of an IP address from the network portion. (308-310)

A mask is a series of initial ones followed by series of final zeros, for a total of 32 bits. Example 1: Sixteen 1s followed by Sixteen 0s: 11111111 11111111 00000000 00000000 - Eight 1's is 255 in dotted decimal notation. - Eight 0's is 0 in dotted decimal notation. - In dotted decimal notation, 255.255.0.0. - In prefix notation, /16.

12. What sort of router connects different networks together, such as a company to an ISP? (307)

Border Routers

11. Suppose you are presented with the following address. 128.89.113.27. What part of this address is the network and what part is the host? (306-307 and notes)

Can't tell, but is always 32 bits

18. Know what each part of a routing table means. (312-317)

Each row represents a route for a range of IP addresses -- often packets going to the same network or subnet.

10. An individual computer on a network is identified by the _?_ portion of the IP address. (306-307)

Host part

7. In IP addressing, what is a network? (306)

In IP addressing, a network is an *organization concept*; it is an organization that controls part of the Internet. It may be a user organization such as a manufacturing corporation or an ISP.

13. What sort of router connects subnets together? (307)

Internal Routers

1. What organization sets TCP/IP standards? (303)

Internet Engineering Task Force (IETF)

5. What is routing? (305)

Is when routers forward incoming packets closer to their destination hosts.

32. What is purpose of the sequence number field? (330-331)

It gives it's position in the stream of segments

8. A version 4 Internet address consists of 4 numbers separated by a period. How many bits is an entire IP address? How many bits is each part? (Figure 8-3, notes and 306)

Network Part = (not always *16* bits) Subnet Part = (not always *8* bits) Host Part = (not always *8* bits) Whole IP Address = *ALWAYS* 32 bits

31. TCP messages are referred to as _?_ (330)

Sequence Numbers

14. What tool is used to separate the host portion of an IP address from the network portion? (308)

Subnet Masks

9. A small network within a larger network is called a _?_ (306)

Subnets

3. What is the only reliable and connection-oriented TCP/IP protocol? (304)

TCP (in the Transport Layer)

23. At what layer is the ARP protocol? (320)

The Internet Layer

21. What is decision caching and why is it used? (317)

because it greatly reduces the work that a router will do for each successive packet

20. If an IP address does not match any of the network prefixes then it will go out on what row? (315)

best match row

26. Why was IPv6 slow to be adopted? (323)

harder to implement

44. Is ICMP reliable? (337)

no, unreliable

45. What is the purpose of ICMP echo messages?

note: pinging

16. In a switch how many possible routes are there for any address? (310)

one single path

43. At what layer does ICMP work? (336)

the Internet Layer

6. What are the major parts of an Internet address? (305-306)

the Network part, Subnet part, and Host part.

22. What protocol is used to match an IP address with a physical address? (318-319)

the address resolution protocol (ARP)

25. What is the main problem with IPv4? (322-323)

the address space is too small