CS4500 Test 4 Study Guide

CS4500 Test 4 Study Guide

Note: This is a study guide, answers may be incorrect, double check and best of luck.

1. A ________ network is totally isolated from the global Internet. Private
2. On a network that uses NAT, the router can use ______ global address(es). A pool of
3. In the sending computer, UDP sends a data unit from the _____ layer. Application
4. TCP uses ____ for error detection. Checksum, Acknowledge and time-out
5. _____ is an IP layer security protocol that only provides integrity and authentication. AH
6. The ______ timer keeps track of the time between the sending of a segment and the receipt of an acknowledgement. Retransmission
7. The definition of reliable delivery includes ______. Error-Free Delivery
8. Which of the following is not part of the UDP user datagram header? Length of Header
9. The _____ defines the server program. Well-Known Port Number
10. If the incoming queue of a UDP client overflows, _____ The user datagrams are discarded and a port unreachable message is sent
11. TCP lies between the ______ and the ______ layers of the TCP/IP protocol suite. Application; Transport
12. Which of the following does UDP guarantee? None of the Above
13. IP is responsible for _____ communication while TCP is responsible for _____ communications.Host-to-host ; Process-to-process
14. The foreign network address of a mobile host with a care-of address of 47.1.2.3./8 is ______. N/A
15. A host can be identified by _____ while a program running on the host can be identified by _______. AN IP address ; a port number
16. A network has addresses that range from 192.168.4.0 to 192.168.5.0. This is probably a(n) _____ network. Private
17. In _____, data are sent or processed at a very inefficient rate, such as 1 byte at a time.  Silly window syndrome
18. The _____ address uniquely identifies a running application program. Socket
19. If a segment carries data along with an acknowledgment, this is called ______. Piggybanking
20. The ____ field is used to order packets of a message. Sequence number
21. If the mobile host is on the same network as the remote host, an inefficient situation called _____ occurs when the remote host sends a message to the mobile host. Triangle Routing
22. Which of the following is not a valid acknowledgement number? 2^32
23. Which field indicates the length of the TCP header? Header Length
24. The source port address on the UDP user datagram header defines _____. The application program of the sending computer
25. The _____ defines the client program. Ephemeral Port Number
26. What is the maximum number of no-operation options in one 32-bit word? 32/8=4
27. If the outgoing queue of a UDP client overflows, ______. The operating system asks the server to wait before any more messages are sent
28. What is the maximum number of the end-of-option options in the entire TCP header?  320/32 = 10
29. To prevent silly window syndrome created by a receiver that processes data at a very slow rate, _____ can be used. Clark’s Solution and Delayed Acknowledgment
30. An ACK number of 1,000 always means that _____. None of the Above
31. The _____ timer prevents a long idle connection between two TPCs. Keep-Alive
32. The _____ timer is needed to handle the zero window-size advertisement. Persistence
33. Karin’s algorithm is used in calculations by the _____ timer. Retransmission
34. Multiply the header length field by ____ to find the total number of bytes in the TCP header. Four
35. A VPN uses ____ to guarantee privacy. IPSec and Tunneling
36. A server issues ____ open while a client issues ____ open. Passive; Active
37. ______ is a collection of protocols that provide security at the IP layer level. IPSec
38. Urgent data requires the urgent pointer field as well as the URG bit in the ____ field. Control
39. Connection establishment involves a ______ handshake; connection termination involves a _____ handshake. Three-way
40. Tunneling is a technique in which the IP datagram is first ____ and then ____ . Encrypted; encapsulated in another datagram
41. On a network that uses NAT, the _____ has a translation table. Router
42. To prevent silly window syndrome created by a sender that sends data at a very slow rate, _____ can be used. Nagle’s Algorithm
43. When the IP layer of a receiving host receives a datagram, _____. Transport Layer protocol takes over
44. If the incoming queue of a UDP servers overflows, ______. The user datagrams are discarded and a port unreachable message is sent
45. _____ is a protocol that provides security at the transport layer level. TLS
46. Which option defines the maximum number of bytes in a TCP segment? Maximum Segment Size
47. An _____ is a private network with limited external access that uses the TCP/IP protocol suite. Extranet
48. The handshake protocol and data exchange protocol are part of _____.  SSH

Short Problem

1. Calculate the UDP checksum for the following binary numbers. Give the results in binary. Use the 16-bit format.

01000111  11100001

00000111  10001001

00000111  10001011

00000111  10001111

 01000111  11100001

+00000111  10001001

 01001000  01101010

 01001000  01101010

+00000111  10001011

 01001111  11110101

 01001111  11110101

+00000111  10001111

 01010000 01110000 <- UDP Checksum

2. The following is dump of a TCP header in hexadecimal format.

05320017 00000001 0000000 500207FF 0000000

a.) What is the source port number (in decimal form)?

05 32 = 1330

b.) What is the destination port number (in decimal form)?

00 17 = 23

c.) What is the sequence number (in decimal form)?

00 00 00 01 = 1

d.) What is the acknowledgement number (in decimal form)?

00 00 00 00 = 0

e.) What is the window size (in decimal form)?

07 FF = 2047 bytes

3. Given the class-A address 16.17.18.20 and mask 255.255.0.0, do starting and broadcast addresses exist for the block? If so, what are they? No

4. A supernet mask is 255.255.248.0. How many class C networks are combined to make this supernet? 8
5. In a class C subnet, we know the IP address of one of the hosts and the mask as given below:

IP address: 182.44.82.16

Mask:          255.255.255.192

What is the first (network address) and the last address (broadcast address) in this      subnet? First 182.44.82.64 - last 182.44.82.127

6. The subnet mask for a class C network is 255.255.255.248. How many subnetworks are available? How many assignable hosts ids per subnet?

2^3-2= 6 subnets ; 2^4= 16 hosts ids per subnet

Problems

1. An ISP is granted a block of classless address starting with 150.80.0.0/16. The ISP wants to distribute blocks of addresses to different customer groups as follows:
1. Customer Group 1: The number of customers in this group is 100. The type of customer is a medium-size business that needs 128 addresses.
2. Customer Group 2: The number of customers in this group is 200. The type of customer is a small-size business that needs 32 addresses.
3. Customer Group 3: The number of customer in this group is 1024. The type of customer is a household that needs 8 addresses.

Design the blocks (ranges) for each customer in slash notation. For a,b and c, only show blocks for the 1st, 2nd and last customer.

               d.) After a, b, and c are satisfied, how many addresses remain for the ISP?

A)

1st Customer	150.80.0.0/16	150.80.0.127/16
2nd Customer	150.80.0.128/16	150.80.0.255/16
100th	150.80.49.128/16	150.80.49.255/16

B

2^5 = 32; 32-5 = 27 prefixes
1st Customer	150.80.50.0/27	150.80.50.31/27
2nd Customer	150.80.50.32/27	150.80.50.63/27
200th Customer	150.80.74.96/16	150.80.74.127/27

C

2^3=8; 32-3=29
1st Customer	150.80.75.0/29	150.80.75.3/29
2nd Customer	150.80.75.4/29	150.80.75.7/29
1024th Customer	150.80.75.251./29	150.80.75.255/29

D

8^16 = 65536 Total available

100*128  = 12800

200*32 = 6400

1024*4 = 4096

65,536 - 12800 - 6400 - 4096 = 42,240 left