Chapter 3 Lab Solutions
Activity Questions Lab 3.1

1. 1 network. Network structure: 192.3.2.
2. C.
3.  2.
4.  2 bits
5. 6 bits
6. 11111111.11111111.11111111.11000000
7. 64
8. 192.3.2.64, 192.3.2.65 - 192.3.2.126,  192.3.2.127
    192.3.2.128, 192.3.2.129  - 192.3.2.190 192.3.2.191
9.  192.3.2.127, 192.3.2.191
10. 192.3.2.65 - 192.3.2.126
     192.3.2.129  - 192.3.2.190
11. 192.3.2.64, 192.3.2.192
12. 
13. 
Review Questions Lab 3.1
1.	When working with IP addresses and subnetting, why is it important to first identify the class of address and the default subnet mask for that class?


2.	What values can a multiplier be?


3.	How do you find the multiplier?


4.	Why must you subtract 2 from 2y when determining the number of usable subnets? 

5.	Why must you subtract 2 from 2x when determining the number of hosts per subnet?


6.	How do you know where to begin incrementing when determining subnet numbers?


7.	When working with IP addresses, which addresses can never be assigned to a host? 


8.	How can you tell that an IP address is a network or subnetwork number if you write out the address in binary?

9.	How can you tell that an IP address is a broadcast address if you write out the address in binary?

10.	Must router interfaces be assigned the first available host address in a range?

Activity Questions Lab 3.2
1.	B.
2.	11111111.11111111.11110000.00000000 – 255.255.240.0, 4 bits borrowed
3.	14
4.	4094
5.	16
6.	172.16.31.0:  10101100.00010000.00011111

7.
172.16.31.17 – 172.16.31.30
 172.16.31.33 – 172.16.31.46
 172.16.31.65 – 172.16.31.78
 172.16.31.97 – 172.16.31.110
 172.16.31.129 – 172.16.31.142
8. 172.16.31.31, 172.16.31.47, 172.16.31.79, 172.16.31.111, 172.16.31.143
9. Number of 1’s in the subnet mask
10. 172.16.31.
Review Questions Lab 3.2
1.	Where do you think the term “bit-count” comes from?
 

2.	What is a benefit of using bit-count notation to express the subnet mask?
 

3.	What would the bit-count notation of the IP address given in this lab have been if there were no subnetting?


4.	If there were no subnetting in this lab, what would the given IP address have represented?

Activity Questions Lab 3.3
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Review Questions Lab 3.3
1.	What makes subnetting with Class A and Class B addresses more difficult than subnetting with Class C addresses?


2.	What is the maximum number of bits that can be borrowed with a Class C address?
 

3.	What is the maximum number of bits that can be borrowed with a Class B address?


4.	What is the maximum number of bits that can be borrowed with a Class A address?


5.	What would the subnet mask be in dotted decimal notation for a Class C address if there were 30 hosts per subnet?

Activity Questions Lab 3.4
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Review Questions Lab 3.4
1.	True or False? Interfaces attached by point-to-point links such as the one between RouterA’s S0 and RouterB’s S1 in Figure 3-2 are on the same network (or subnetwork).
 

2.	What kind of IP address is indicated by all binary ones in the host portion?
 

3.	What kind of IP address is indicated by all binary zeroes in the host portion?
 

4.	In every subnet created, why are two IP addresses unusable?
 

5.	What is the purpose of a subnet mask?
 

6.	What might you do if, when you borrowed enough bits for subnet numbers, you were not left with enough bits for host numbers?

Activity Questions Lab 3.5
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Review Questions Lab 3.5
1.	Explain your destination MAC address entry in Figure 3-4.
 

2.	What will all hosts that see an ARP request do with the information?
 

3.	How does a sending computer know a destination computer’s IP address?
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4.	What type of frame is the ARP reply—unicast or broadcast?

5.	Because ARP uses bandwidth by broadcasting, exactly how does ARP save bandwidth overall?

Activity Questions Lab 3.6
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2.	Destination MAC:                                              Source MAC:  
Review Questions Lab 3.6
1.	What kind of address is the destination MAC address in a RARP request?
 

2.	How does a computer know its own MAC address?
 

3.	Based on your lab activity, explain your entry for the source IP address in the RARP request.
 

4.	What kind of address is the destination IP address in an RARP request?
 

5.	How does the RARP server know which IP address to assign to an RARP client?

Activity Questions Lab 3.7
1.	Destination IP:                                                        Source IP: 
2.	Destination MAC:                                                   Source MAC:  
3.	Destination IP:                                                       Source IP: 
4.	Destination MAC:                                                   Source MAC:  
Review Questions Lab 3.7
1.	In Figure 3-9, what is the default gateway for computer A?
 

2.	In Figure 3-9, what is the default gateway for Computer B?
 

3.	What can you say about the source and destination IP addresses in a frame as the data travels across routers in its journey from original sender to ultimate receiver?
 

4.	What can you say about the source and destination MAC addresses in a frame as the data travels across routers in its journey from original sender to ultimate receiver?
 

5.	Where do routers get the information necessary to make forwarding decisions?
 

6.	Why do computers usually need a default gateway, and when is it used?
 
Activity Questions Lab 3.8
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Review Questions Lab 3.8
1.	For what purposes is the binary numbering system used in networking?

2.	For what purposes is the hexadecimal numbering system used in networking?

3.	Why does it require fewer hexadecimal numerals than binary numerals to express any given number?

4.	True or False? Some numbers are too large to be expressed in binary.