Universidad Del TuraboTCOM 503 – Introduction to TCP/IPExam 1

Roberto Clausell-Rivera S00573311September 19, 2008

Question 1

OSI Model and TCP/IP are related because both of them are layered models. The first four layers functions of the OSI model corresponds to the first four layers of the TCP/IP. The three uppermost layers of OSI model are represented by the Application layer of TCP/IP. In both models each layer receives services from the immediate layer below it and the communication is peer-to-peer between layers. In other words, the information send from the application layer is understandable only by the application layer at the receiving node, and so on.

Question 2

Tasks OSI Model Layer TCP/IP Layer

Route Determination Network Internetwork

Flow Control Data Link and Transport

Data Link and Transport

Interface Transmission Media Physical Physical

Provides access for the end user Application Application

Reliable process-to-process message delivery Transport Transport

Route Selection Network Internetwork

Defines frames Data Link Data Link

Provides user services such as email and file transfer Application Application

Transmission of bit stream across physical medium Physical Physical

Format and code conversion services Presentation Application

Question 3

Routers, switches and bridges are networking equipments that break up collisions. IPX uses 10 byte addresses or 80 bits. IPX is a 32 bit network address followed by a 48 bit host. Routers supports from Layer 1 to Layer 3 of the OSI Model (Physical, Data Link and Network Layers). ICMP, IGMP and IP are three of the TCP/IP Internetwork Layer Protocols. Besides ARP and RARP TCP/IP Internetwork Layer Protocols too. UDP (User Datagram Protocol) is the TCP/IP Transport Layer Protocol that provides end-to-end, best effort, transaction oriented, and connectionless service.

Question 4

TCP/IP Protocol Suite and OSI model are similar because both of them are layered models. TCP/IP Protocol Suite is a made of five layers while OSI model is a seven layers model. The Application layer in TCP/IP is equivalent to the combined session, presentation and application layers of the OSI model. Transport, Network, Data Link and Physical are present on both models.

The layers in TCP/IP Protocol suite are not necessarily interdependent, but contain relatively independent protocols that can be mixed and match depending on the needs. In the OSI model, each layer functions are specified, and these functions are independent from layer to layer.

Another important difference is that TCP/IP is a hierarchical protocol suite, while the OSI model is a layered framework for the design of network systems that allows communication between any kinds of computer systems. OSI model is not a protocol, but it is a guideline for understanding and designing a network infrastructure flexible, robust and interoperable.

Problem 5

IP address Binary Notation Hexadecimal Class

114.34.2.8 01110010.00100010.00000010.00001000 0x72220208 Class A 114.0.0.0

129.14.6.8 10000001.00001110.00000110.00001000 0x810E0608 Class B 129.14.0.0

208.31.54.12 11010000.00011111.00110110.00001100 0xD01F360C Class C 208.31.54.0

238.34.2.1 11101110.00100010.00000010.00000001 0xEE220201 Class D It is a multicast address It is a

241.34.2.8 11110001.00100010.00000010.00001000 0xF1220208 Class E

14.34.2.8 00001110.00100010.00000010.00001000 0x0E220208 Class A 14.0.0.0

229.14.6.8 11100101.00001110.00000110.00001000 0xE50E0608 Class D It is a multicast address It is a

28.31.54.12 00011100.00011111.00110110.00001100 0x1C1F360C Class A 28.0.0.0

138.34.2.1 10001010.00100010.00000010.00000001 0x8A220201 Class B 138.34.0.0

191.34.2.8 10111111.00100010.00000010.00001000 0xBF220208 Class B 191.34.0.0

Problem 6

Source Address 128.23.67.3 10000000.00010111.01000011.00000011

Mask 255.255.0.0 11111111.11111111.00000000.00000000

Net id = 128.23.0.0

Destination Address 128.45.23.3 10000000.00101101.00010111.00000011

Mask 255.255.0.0 11111111.11111111.00000000.00000000

AND 10000000.00101101.00000000.00000000

Net id = 128.45.0.0

They are both class B networks. When we compare the network ids of both ip addresses (assuming no subnetting) they are in different networks, therefore the message needs to travel through a router to get to the destination.

Source Address 128.23.67.3

Mask 255.255.0.0 Class B

Net id =128.23.0.0

Destination Address 128.45.23.70

Mask 255.255.0.0 Class B

Net id = 128.45.0.0

They are both class B networks. When we compare the network ids of both ip addresses (assuming no subnetting) they are in different networks, therefore the message needs to travel through a router to get to the destination.

Source Address 18.23.67.3

Mask 255.0.0.0 Class A

Net id = 18.0.0.0

Destination Address 18.23.23.7

Mask 255.0.0.0 Class A

Net id = 18.0.0.0

They are both class A networks. When we compare the network ids of both ip addresses (assuming no subnetting) they are in the same network, therefore the message does not need to travel through a router to get to the destination.

Source Address 198.23.67.3

Mask 255.255.255.0 Class C

Net id = 198.23.67.0

Destination Address 198.45.23.7

Mask 255.255.255.0 Class C

Net id = 198.45.23.0

They are both class C networks. When we compare the network ids of both ip addresses (assuming no subnetting) they are in different networks, therefore the message needs to travel through a router to get to the destination.

Source Address 193.23.67.65 11000001.00010111.01000011.01000001

Class C

Default Netmask 255.255.255.0

Subnet Mask 255.255.255.192 11111111.11111111.11111111.11000000

Net id 11000001.00010111.01000011.01000000

193.24.67.64

First Address 193.24.67.65

Last Address 193.24.67.126

Broadcast Address 193.24.67.127

Destination Address 193.23.67.147 11000001.00010111.01000011.10010011

Class C

Default Netmask 255.255.255.0

Subnet Mask 255.255.255.192 11111111.11111111.11111111.11000000

Net id 11000001.00010111.01000011.10000000

193.24.67.128

First Address 193.24.67.129

Last Address 193.24.67.190

Broadcast Address 193.24.67.191

The network address for the first ip address is 193.24.67.63 and for the second one is 193.24.67.128. . The hosts are in different networks; therefore the message needs to travel through a router to get to the destination host.

Problem 7

IP: 135.134.11.66 Mask: 255.255.192.0

Default Mask Class B (255.255.0.0)

#bit = 2 ->4 subnets

# hosts/subnet = 214-2=16382

135.134.11.66 10000111.10000110.00001011.01000010

First Subnet 10000111.10000110.00000000.00000000

135.134.0.0

10000111.10000110.00111111.11111111

135.134.63.255

Second Subnet 10000111.10000110.01000000.00000000

135.134.64.0

10000111.10000110.01111111.11111111

135.134.127.255

Target IP Address Target IP Address Subnet mask Subnet mask

135.134.11.66 135.134.11.66 255.255.192.0 255.255.192.0

Network ID Network Address Subnet Usable Address

Range Broadcast

1 135.134.0.0 135.134.0.1-135.134.63.254 135.134.63.255

2 135.134.64.0 135.134.64.1-135.134.127.254 135.134.127.255

3 135.134.128.0 135.134.128.1-135.134.191.254 135.134.191.255

4 135.134.192.0 135.134.192.1-135.134.255.254 135.134.255.255

Note: In classful subnetting the first and last networks are not usable because they are reserved for network and broadcast addresses, respectively.

IP: 192.44.82.16 Mask 255.255.255.192

Default Mask Class C (255.255.255.0)

#bit = 2 ->4 subnets

# hosts/subnet = 26-2 = 62

Target IP Address Target IP Address Subnet mask Subnet mask

192.44.82.16 192.44.82.16 255.255.255.192 255.255.255.192

Network ID Network Address Subnet Usable Address

Range Broadcast

1 192.44.82.0 192.44.82.1-192.44.82.62 192.44.82.63

2 192.44.82.64 192.44.82.65-192.44.82.126 192.44.82.127

3 192.44.82.128 192.44.82.129-192.44.82.190 192.44.82.191

4 192.44.82.192 192.44.82.193-192.44.82.254 192.44.82.255

Note: In classful subnetting the first and last networks are not usable because they are reserved for network and broadcast addresses, respectively.

IP: 25.34.12.56 Mask: 255.224.0.0

Default Mask Class A (255.0.0.0)

#bit = 3 ->8 subnets

# hosts/subnet = 221-2 = 2097150

Target IP Address Target IP Address Subnet mask Subnet mask

25.34.12.56 25.34.12.56 255.224.0.0 255.224.0.0

Network ID Network Address

Subnet Usable Address Range Broadcast

1 25.0.0.0 25.0.0.1-25.31.255.254 25.31.255.255

2 25.32.0.0 25.32.0.1-25.32.255.254 25.32.255.255

3 25.64.0.0 25.64.0.1-25.64.255.254 25.64.255.255

4 25.96.0.0 25.96.0.1-25.96.255.254 25.96.255.255

5 25.128.0.0 25.128.0.1-25.128.255.254 25.128.255.255

6 25.160.0.0 25.160.0.1-25.160.255.254 25.160.255.255

7 25.192.0.0 25.192.0.1-25.192.255.254 25.192.255.255

8 25.224.0.0 25.224.0.1-25.224.255.254 25.224.255.255

Note: In classful subnetting the first and last networks are not usable because they are reserved for network and broadcast addresses, respectively.

IP: 133.135.112.66 Mask: 255.255.224.0

Default Mask Class B (255.255.0.0)

#bit = 3 ->8 subnets

# hosts/subnet = 213-2 = 8190

Target IP Address Target IP Address Subnet mask Subnet mask

133.135.112.66 133.135.112.66 255.255.224.0 255.255.224.0

Network ID Network Address Subnet Usable Address

Range Broadcast

1 133.135.0.0 133.135.0.1-133.135.31.254 133.135.31.255

2 133.135.32.0 133.135.32.1-133.135.63.254 133.135.63.255

3 133.135.64.0 133.135.64.1-133.135.95.254 133.135.95.255

4 133.135.96.0 133.135.96.1- 133.135.127.255

133.135.127.254

5 133.135.128.0 133.135.128.1-133.135.159.254 133.135.159.255

6 133.135.160.0 133.135.160.1-.133.135.191.254 133.135.191.255

7 133.135.192.0 133.135.192.1-133.135.223.255 133.135.223.255

8 133.135.224.0 133.135.224.1-133.135.255.254 133.15.255.255

Note: In classful subnetting the first and last networks are not usable because they are reserved for network and broadcast addresses, respectively.

IP: 10.34.12.56 Mask: 255.240.0.0

Default Mask Class A (255.255.0.0)

#bit = 4 ->16 subnets

# hosts/subnet = 220-2 = 1048574

Target IP Address Target IP Address Subnet mask Subnet mask

10.34.12.56 10.34.12.56 255.240.0.0 255.240.0.0

Network ID Network Address

Subnet Usable Address Range Broadcast

1 10.0.0.0 10.0.0.1-10.15.255.254 10.15.255.255

2 10.16.0.0 10.16.0.1-10.31.255.254 10.31.255.255

3 10.32.0.0 10.32.0.1-10.47.255.254 10.47.255.255

4 10.48.0.0 10.48.0.1-10.63.255.254 10.63.255.255

5 10.64.0.0 10.64.0.1-10.79.255.254 10.79.255.255

6 10.80.0.0 10.80.0.1-10.95.255.254 10.95.255.255

7 10.96.0.0 10.96.0.1-10.111.255.254 10.111.255.255

8 10.112.0.0 10.112.0.1-10.127.255.254 10.127.255.255

9 10.128.0.0 10.128.0.1-10.143.255.254 10.143.255.255

10 10.144.0.0 10.144.0.1-10.159.255.254 10.159.255.255

11 10.160.0.0 10.160.0.1-10.175.255.254 10.175.255.255

12 10.176.0.0 10.176.0.1-10.191.255.254 10.191.255.255

13 10.192.0.0 10.192.0.1-10.207.255.254 10.207.255.255

14 10.208.0.0 10.208.0.1-10.223.255.254 10.223.255.255

15 10.224.0.0 10.224.0.1-10.239.255.254 10.239.255.255

16 10.240.0.0 10.240.0.1-10.255.255.254 10.255.255.255

Note: In classful subnetting the first and last networks are not usable because they are reserved for network and broadcast addresses, respectively.

Problem 8

Data given:

115 remote offices

Class B 190.17.0.0/16

200 hosts per subnet initially

500 hosts per subnet expected

10 networks reserved for future use

Solution:

#bit hosts = [log2 500] = 9

16 7 9

Net id Subnet id Hosts

I would choose 190.17.0.0/23.

Total Subnets = 27 = 128 subnets

Usable subnets = 128 subnets

Total hosts per subnet = 29-2 = 510

Total hosts per subnet left unused after expected growth met = 10

Networks for future use = 10

Subnets left over = 128-115-10 = 3 networks available

Problem 9

Data given:

14 remote offices

Class B 190.18.0.0/16

200 hosts per subnet initially

500 hosts per subnet expected growth

10 networks reserved for future use

Solution:

#bit hosts = [log2 500] = 9

16 bits 7 bits 9 bits

Net id Subnet id Hosts

I would choose 190.18.0.0/23.

Total Subnets = 27 = 128 subnets

Usable subnets = 128 subnets

Total hosts per subnet = 29-2 = 510

Total hosts per subnet left unused after expected growth met = 10

Networks for future use = 10

Subnets left over = 128-14-10 = 104

Note: for the design I used the network 190.18.254.255/23 and subnet it on /30 addresses to assign them on the WAN links. Besides, we have to reserve 10 more of this /30 networks for the future wan links. Therefore, we have to subtract this addresses to the subnets left over, hence we still have 103 /23 subnets to use and 103 /30 network for future use.

Network Scheme Drawing

In each LAN site the router will have assigned the first usable address of each sub-network. At the WAN site, the remote office router will have the odd ip address of the two usable ip addresses, in the /30 sub-networks, and the Main Office Core Router will have assigned the even ip address.

For the internet WAN link the Main Office Core Router will have assigned the odd ip address of the two usable ip addresses, in this case 190.18.254.57/30.

IP Table for above drawing

190.18.0.0/23 for LAN Segments 190.18.0.0/23 for LAN Segments 190.18.0.0/23 for LAN Segments 190.18.0.0/23 for LAN Segments 190.18.0.0/23 for LAN Segments 190.18.0.0/23 for LAN Segments

Net ID

Network address Usable range Usable range

Broadcast Comments

1 190.18.0.0/23 190.18.0.1/23 190.18.1.254/23 190.18.1.255/23 USED

2 190.18.2.0 190.18.2.1 190.18.3.254 190.18.3.255 USED

3 190.18.4.0 190.18.4.1 190.18.5.254 190.18.5.255 USED

4 190.18.6.0 190.18.6.1 190.18.7.254 190.18.7.255 USED

5 190.18.8.0 190.18.8.1 190.18.9.254 190.18.9.255 USED

6 190.18.10.0 190.18.10.1 190.18.11.254 190.18.11.255 USED

7 190.18.12.0 190.18.12.1 190.18.13.254 190.18.13.255 USED

8 190.18.14.0 190.18.14.1 190.18.15.254 190.18.15.255 USED

9 190.18.16.0 190.18.16.1 190.18.17.254 190.18.17.255 USED

10 190.18.18.0 190.18.18.1 190.18.19.254 190.18.19.255 USED

11 190.18.20.0 190.18.20.1 190.18.21.254 190.18.21.255 USED

12 190.18.22.0 190.18.22.1 190.18.23.254 190.18.23.255 USED

13 190.18.24.0 190.18.24.1 190.18.25.254 190.18.25.255 USED

14 190.18.26.0 190.18.26.1 190.18.27.254 190.18.27.255 USED

15 190.18.28.0 190.18.28.1 190.18.29.254 190.18.29.255 RESERVED

16 190.18.30.0 190.18.30.1 190.18.31.254 190.18.31.255 RESERVED

17 190.18.32.0 190.18.32.1 190.18.33.254 190.18.33.255 RESERVED

18 190.18.34.0 190.18.34.1 190.18.35.254 190.18.35.255 RESERVED

19 190.18.36.0 190.18.36.1 190.18.37.254 190.18.37.255 RESERVED

20 190.18.38.0 190.18.38.1 190.18.39.254 190.18.39.255 RESERVED

21 190.18.40.0 190.18.40.1 190.18.41.254 190.18.41.255 RESERVED

22 190.18.42.0 190.18.42.1 190.18.43.254 190.18.43.255 RESERVED

23 190.18.44.0 190.18.44.1 190.18.45.254 190.18.45.255 RESERVED

24 190.18.46.0 190.18.46.1 190.18.47.254 190.18.47.255 RESERVED

IP addresses for the WAN (point to point connection) IP addresses for the WAN (point to point connection) IP addresses for the WAN (point to point connection) IP addresses for the WAN (point to point connection) IP addresses

for the WAN (point to point connection) IP addresses for the WAN (point to point connection)

Net ID

Network address Usable range Usable range

Broadcast Comments

25 190.18.254.0/30 190.18.254.1/30 190.18.254.2/30 190.18.254.3/30 USED

26 190.18.254.4 190.18.254.5 190.18.254.6 190.18.254.7 USED

27 190.18.254.8 190.18.254.9 190.18.254.10 190.18.254.11 USED

28 190.18.254.12 190.18.254.13 190.18.254.14 190.18.254.15 USED

29 190.18.254.16 190.18.254.17 190.18.254.18 190.18.254.19 USED

30 190.18.254.20 190.18.254.21 190.18.254.22 190.18.254.23 USED

31 190.18.254.24 190.18.254.25 190.18.254.26 190.18.254.27 USED

32 190.18.254.28 190.18.254.29 190.18.254.30 190.18.254.31 USED

33 190.18.254.32 190.18.254.33 190.18.254.34 190.18.254.35 USED

34 190.18.254.36 190.18.254.37 190.18.254.38 190.18.254.39 USED

35 190.18.254.40 190.18.254.41 190.18.254.42 190.18.254.43 USED

36 190.18.254.44 190.18.254.45 190.18.254.46 190.18.254.47 USED

37 190.18.254.48 190.18.254.49 190.18.254.50 190.18.254.51 USED

38 190.18.254.52 190.18.254.53 190.18.254.54 190.18.254.55 USED

39 190.18.254.56 190.18.254.57 190.18.254.58 190.18.254.59 Internet

WAN link

40 190.18.254.60 190.18.254.61 190.18.254.62 190.18.254.63 RESERVED

41 190.18.254.64 190.18.254.65 190.18.254.66 190.18.254.67 RESERVED

42 190.18.254.68 190.18.254.69 190.18.254.70 190.18.254.71 RESERVED

43 190.18.254.72 190.18.254.73 190.18.254.74 190.18.254.75 RESERVED

44 190.18.254.76 190.18.254.77 190.18.254.78 190.18.254.79 RESERVED

45 190.18.254.80 190.18.254.81 190.18.254.82 190.18.254.83 RESERVED

46 190.18.254.84 190.18.254.85 190.18.254.86 190.18.254.87 RESERVED

47 190.18.254.88 190.18.254.89 190.18.254.90 190.18.254.91 RESERVED

48 190.18.254.92 190.18.254.93 190.18.254.94 190.18.254.95 RESERVED

49 190.18.254.96 190.18.254.97 190.18.254.98 190.18.254.99 RESERVED

Problem 10

Data given:

Block of addresses 121.88.0.0/16

300 medium size businesses with 128 addresses each 500 small business with 16 addresses each 1200 households with 4 addresses each

Solution:

# bits hosts = [log2128] = 7 bits

16 bits 9 bits 7 bits

Net id Subnet id Hosts

121.88.0.0/25

First Network 121.88.0.0/25 to 121.88.0.127/25

Second Network 121.88.0.128/25 to 121.88.0.255/25

Third Network 121.88.1.0/25 to 121.88.1.127/25

Fourth Network 121.88.1.128/25 to 121.88.1.255/25

300 Networks/2 addresses blocks =150

Total Block for 300 networks of 128 addresses each = 121.88.0.0/25 to 121.88.149.255/25

#bits hosts = [log216] = 4 bits

16 bits 12 bits 4 bits

Net id Subnet id Hosts

121.88.150.0/28

First Network 121.88.150.0/28 to 121.88.150.15/28

Second Network 121.88.150.16/28 to 121.88.150.31/28

256 IP addresses/16 IP addresses per network = 16 addresses blocks

500 Networks/16 addresses blocks =32

Total Block for 500 networks of 16 addresses each = 121.88.150.0/28 to 121.88.181.255/28

#bits hosts = [log24] = 2

16 bits 14 bits 2 bits

Net id Subnet id Hosts

121.88.182.0/30

First Network 121.88.182.0/30 to 121.88.182.3/30

Second Network 121.88.182.4/30 to 121.88.182.7/30

256 IP addresses/4 IP addresses per subnet = 64 addresses blocks

1200 Networks/64 addresses blocks = 19

Total Block for 1200 networks of 4 addresses each = 121.88.150.0/30 to 121.88.168.255/30

Total IP addresses = 216 =65536

IP addresses used:

300*128 = 38400

500*16 = 8000

1200*4 = 480051200

Total Available IP addresses = 65536-51200 = 14336 still available IP addresses for future use