vlsm work book

101010010001111100

1011100101011100101100011101001101111010001101000001010010110010100101010110011111110101010001011101001101010011001010010101010101010100011001001010100101100011010110001101011010100001011001010100110100101001001.0172.16.1.0 192.168.10.0010

10.250.1.0172.31.15.0

192.168.10.96192.168.10.126

Version 1.0

VLSMWorkbook

Variable-Length Subnet Mask

Version 2.0

Student Name:

IP Address Classes

Class A 1 127 (Network 127 is reserved for loopback and internal testing)Leading bit pattern 0 00000000.00000000.00000000.00000000

Class B 128 191 Leading bit pattern 10 10000000.00000000.00000000.00000000

Class C 192 223 Leading bit pattern 110 11000000.00000000.00000000.00000000

Class D 224 239 (Reserved for multicast)

Class E 240 255 (Reserved for experimental, used for research)

Private Address Space

Class A 10.0.0.0 to 10.255.255.255

Class B 172.16.0.0 to 172.31.255.255

Class C 192.168.0.0 to 192.168.255.255

Default Subnet Masks

Class A 255.0.0.0

Class B 255.255.0.0

Class C 255.255.255.0

Network . Host . Host . Host

Network . Network . Host . Host

Network . Network . Network . Host

Inside Cover

This workbook assumes you already have a background in subnetting. If you dont you maywant to consider completing the IP Addressing and Subnetting Workbook.

Produced by: Robb [email protected] and/or [email protected]

Frederick County Career & Technology CenterCisco Networking Academy

Frederick County Public SchoolsFrederick, Maryland, USA

Special Thanks to Melvin Baker and Jim Dorschfor taking the time to check this workbook for errors.

Workbooks included in the series:

IP Addressing and Subnetting WorkbooksACLs - Access Lists Workbooks

VLSM Variable-Length Subnet Mask IWorkbooks

Classful vs. ClasslessSubnetting

When youre subnetting an IP address for a network you have twooptions: classful and classless. Classful subnetting is the simplest method.It tends to be the most wasteful because it uses more addresses than arenecessary. In classful subnetting you use the same subnet mask for eachsubnet, and all the subnets have the same number of addresses in them.

Classless addressing allows you to use different subnet masks andcreate subnets tailored to the number of users in each group. This techniqueis referred to as VLSM, Variable Length Subnet Masks.

What is VLSM

Variable Length Subnet Masks allow you a much tighter control overyour addressing scheme. If you use a class C address with a default subnetmask you end up with one subnet containing 256 addresses. By using VLSMyou can adjust the number of subnets and number of addresses dependingon the specific needs of your network. The same rules apply to a class A orB addresses.

VLSM is supported by the following protocols: RIP version 2, OSPF,EIGRP, Dual IS-IS, and BGP. You need to configure your router for VariableLength Subnet Masks by setting up one of these protocols. Then configurethe subnet masks of the various interfaces in the IP address interface sub-command.

Benefits of VLSM

Allows efficient use of address spaceAllows the use of multiple subnet mask lengthsBreaks up an address block into smaller custom blocksAllows for route summarizationProvides more flexibility in network designSupports hierarchical enterprise networks

This workbook explores three different methods to figure out sub-subnets:the box method, the circle method, and a VLSM chart.

1

Classful SubnettingExample

When youre subnetting an IP address for a network you have twooptions: classful and classless. Classful subnetting is the simplest method.It also tends to be the most wasteful because it uses more addresses thanare necessary. In classful subnetting you use the same subnet mask foreach subnet, and all the subnets have the same number of addresses inthem.

In this example you need five subnets, each one containing 30 hosts.The serial connections only require two address each so you are wasting 28usable addresses in each of the serial subnet ranges.

192.168.1.0192.168.1.32192.168.1.64192.168.1.96192.168.1.128192.168.1.160192.168.1.192192.168.1.224

192.168.1.31192.168.1.63192.168.1.95192.168.1.127192.168.1.159192.168.1.191192.168.1.223192.168.1.255

totototototototo

/27255.255.255.224

32 Hosts8 Subnets

Marketing25 Hosts Records

12 Hosts

Research30 Hosts

IP Address: 192.168.1.0

0

255

128

6364 192

191

32

31

95

96159

223

224

160

127

The Box Methodfor visualizing subnets

/27/27/27/27/27/27/27/27

2

Classful Subnet Ranges

Classless SubnettingExample

Classless addressing allows you to use different subnet masksand create subnets tailored to the number of users in each subnetwork.There are fewer wasted IP addresses using smaller subnets.

In this example you need at total of five subnets, two containing 30hosts, one containing 12 hosts, and two serial connections that only requiretwo usable addresses each.

By adjusting the subnet masks you can cut your address usage byalmost half in this example. This type of subnetting requires a networkprotocol which will support it such as: RIP version 2, EIGRP, OSPF, or BGP.

Marketing25 Hosts Records

12 Hosts

Research30 Hosts

IP Address: 192.168.1.0

0

255

79

128

6364

32

3196

83

87

80

18412795

88

192.168.1.0192.168.1.32192.168.1.64192.168.1.80192.168.1.84192.168.1.88192.168.1.96192.168.1.128

192.168.1.31192.168.1.63192.168.1.79192.168.1.82192.168.1.87192.168.1.95192.168.1.127192.168.1.255

totototototototo

/27/27/28/30/30/29/27/25

3

The Box Methodfor visualizing subnets

Classless Subnet Ranges

/24255.255.255.0

256 Hosts1 Subnet

Start with a square. The whole squareis a single subnet comprised of 256addresses.

Visualizing Subnets UsingThe Box Method

The box method is a simple way to visualize the breakdown of subnetsand addresses into smaller sizes. By shading or coloring in the boxes youcan easily break up your subnets without overlapping your addresses. Youadjust each subnet to the correct size needed.

/25255.255.255.128

128 Hosts2 Subnets

/26255.255.255.192

64 Hosts4 Subnets

4

Split the box in half and you get twosubnets with 128 addresses.

Divide the box into quarters and youget four subnets with 64 addresses.

5/27255.255.255.224

32 Hosts8 Subnets

Split each individual square and youget eight subnets with 32 addresses.

/30255.255.255.252

4 Hosts64 Subnets

/29255.255.255.248

8 Hosts32 Subnets

/28255.255.255.240

16 Hosts16 Subnets

Split the boxes in half again and youget sixteen subnets with sixteenaddresses.

The next split gives you thirty twosubnets with eight addresses.

The last split gives sixty four subnetswith four addresses each.

Color in the squares used with differentshades to highlight each subnet.

VLSM AddressingBox Method

(Sample)Problem 1

Using the network diagram and information given create an addressingscheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe box. This business will be using the class C address 220.10.10.0. Re-member to start with your largest groups first.

MarketingDepartment

60 Hosts

LAN Address:

220.10.10.0/26

ResearchDepartment

28 Hosts

LAN Address:

220.10.10.64/27

0

255127

128

6364

95

96

6


(Sample)Problem 2

Using the network diagram and information given create an addressingscheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe box. This company will be using the class C address 192.168.16.0. Re-member to start with your largest groups first.

Washington D.C.120 Hosts

Frederick20 Hosts

Baltimore60 Hosts

0

255127

128

192191

223

LAN Address:

192.168.16.0/25

LAN Address:

192.168.16.192/27LAN Address:

192.168.16.128/26

WAN Address #1:

192.168.16.224/30 WAN Address #2:192.168.16.228/30

227

239231

224 232

228

240


7

8VLSM AddressingBox Method

Problem 3Using the network diagram and information given create an addressing

scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe box. This company will be using the class C address 190.10.10.0. Re-member to start with your largest groups first.

Dallas60 Hosts

Ft. Worth25 Hosts

LAN Address:

LAN Address:

WAN Address #1:


0

255

128

6364

95

96

99

103 111

127

104

100

112



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe box. This company will be using the class C address 220.108.38.0. Re-member to start with your largest groups first.

Corpus Christi25 Hosts

Waco50 Hosts

Houston120 Hosts

LAN Address:

LAN Address:LAN Address:

WAN Address #1:WAN Address #2:


9

0 12832 160

15 4739 175167135 1437

11 4335 171163131 1393

27 5951 187179147 15519

31 6355 191183151 15923

75 10799 235227195 20367

79 111103 239231199 20771

91 123115 251243211 21983

95 127119 255247215 22387

408 136 168

4 13236 1644412 140 172

16 14448 1765624 152 184

20 14852 1806028 156 188

64 19296 22410472 200 232

68 196100 22810876 204 236

80 208112 24012088 216 248

84 212116 24412492 220 252

10



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets usedin the box. This company will be using the class C address 192.168.10.0.Remember to start with your largest groups first.

New York115 Hosts

Fargo23 Hosts

LAN Address:

LAN Address:

WAN Address #2:


San Jose

12 Hosts

48 Hosts

LAN Address:

LAN Address:

WAN Address #1:

0 12832 160

15 4739 175167135 1437

11 4335 171163131 1393

27 5951 187179147 15519

31 6355 191183151 15923

75 10799 235227195 20367

79 111103 239231199 20771

91 123115 251243211 21983

95 127119 255247215 22387

408 136 168

4 13236 1644412 140 172

16 14448 1765624 152 184

20 14852 1806028 156 188

64 19296 22410472 200 232

68 196100 22810876 204 236

80 208112 24012088 216 248

84 212116 24412492 220 252



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets usedin the box. This company will be using the class C address 222.10.150.0.Remember to start with your largest groups first.

Boston

LAN Address:

WAN Address #1:

Draw the necessary lines and color in the used squareswith different shades to highlight each subnet.

11

London

WAN Address #2:

6 Hosts

12 Hosts

LAN Address:

24 Hosts 37 Hosts

LAN Address:

LAN Address:

0

255

128

6364 192

191

32

31

95

96159

223

224

160

127

Toyko

12



scheme which utilizes variable-length subnet masks. Show the subnetaddress and subnet mask in the boxes below, color or shade the sub-subnetsused in the box. This company will be using the class C address 200.150.70.0.Remember to start with your largest groups first.


Boston 2

LAN Address:

6 Hosts

12 Hosts

LAN Address:

LAN Address:

14 Hosts

LAN Address:

25 Hosts

0

255127

128

6364 192

191

Serial Address:

Boston 1



scheme which utilizes variable-length subnet masks. Show the subnetaddress and subnet mask in the boxes below, color or shade the sub-subnetsused in the box. This company will be using the class C address 192.168.24.0.Remember to start with your largest groups first.

LAN Address:


13

London

WAN Address #2:

18 Hosts

LAN Address:

95 Hosts 12 Hosts

LAN Address:

LAN Address:

0

34 Hosts

255

WAN Address #1:

Paris

New York

/24255.255.255.0

256 Hosts1 Subnet

Start with a circle. The whole circle isa single subnet comprised of 256addresses.

Visualizing Subnets UsingThe Circle Method

The circle method is another method used to visualize the breakdownof subnets and addresses into smaller sizes. By shading or coloring in thedifferent sections of the circle you can easily break up your subnets withoutoverlapping your addresses. You adjust each subnet to the correct sizeneeded.

/25255.255.255.128

128 Hosts2 Subnets

/26255.255.255.192

64 Hosts4 Subnets

Split the circle in half and you get twosubnets with 128 addresses.

Divide the circle into quarters andyou get four subnets with 64addresses.

.0

.127.128

.255

.0

.127.128

.255

.63

.64.191.192

14

/27255.255.255.224

32 Hosts8 Subnets

Split each quarter and you get eightsubnets with 32 addresses.

/30255.255.255.252

4 Hosts64 Subnets

/29255.255.255.248

8 Hosts32 Subnets

/28255.255.255.240

16 Hosts16 Subnets

Split the boxes in half again and youget sixteen subnets with sixteenaddresses.

The next split gives you thirty twosubnets with eight addresses.

The last split gives sixty four subnetswith four addresses each.

.0

.127.128

.255

.63

.64.191.192

.31.32

.95.96.159

.160

.223.224

.0

.31

.15.16

.64

.63

.48.47

.32

.111.96

.95

.80.79

.112.127

.176

.224.223

.192

.208.207

.191

.175

.159

.143

.160

.144

.128

.255.239

.240

15

.0 -

.7

.24 - .

31.8 -

.15

.16 -

.23

.64 - .71

.56 - .63.48 - .

55.40

- .47.32

- .39

.104 - .111.96 - .103

.88 - .95

.80 - .87

.72 - .79

.112 - .119

.120 - .127

.176 - .183

.224 -

.231

.216 -

.223

.192 - .199

.208 - .2

15

.200 - .207

.184 - .191

.168. - 175

.152 - .159

.136 - .143

.160 - .167 .144 - .151

.128 - .135

.248

- .2

55

.232

- .23

9

.240

- .24

7

.0 - .

3

.24 - .

27

.8 - .

11

.16 -

.19

.64 - .67

.56 - .59

.48 - .51

.40 - .4

3.32

- .35

.104 - .107.96 - .99

.88 - .91

.80 - .83

.72 - .75

.112 - .115

.120 - .123.176 - .179

.224 -

.227

.216 -

.219

.192 - .195

.208 - .21

1

.200 - .203

.184 - .187

.168. - 171

.152 - .155 .136 - .139

.160 - .163

.144 - .147

.128 - .131

.248

- .2

51

.232

- .23

5

.240

- .24

3

.4 - .

7

.12

- .15

.20 -

.23

.28 - .

31

.36 - .

39

.44 - .47

.52 - .55

.60 - .63

.68 - .71

.76 - .79

.84 - .87.92 - .95

.100 - .103

.108 - .111

.116 - .119

.124 - .127

.132 - .135

.140 - .143.148 - .151

.156 - .159

.164 - .167

.172. - 175

.180 - .183

.188 - .191

.196 - .199

.204 - .207

.212 - .

215.22

0 - .2

23 .228

- .23

1

.236

- .23

9

.244

- .2

47

.252

- .2

55

16

Color in the necessary circle sections used with differentshades to highlight each subnet.

VLSM AddressingCircle Method

(Sample)Problem 9

Using the network diagram and information given create an addressingscheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This business will be using the class C address 220.10.10.0.Remember to start with your largest groups first.

MarketingDepartment

60 Hosts

LAN Address:

220.10.10.0/26

ResearchDepartment

28 Hosts

LAN Address:

220.10.10.64/27

.0.255

.127.128

.96

.63

.95

.64

17


(Sample)Problem 10

Using the network diagram and information given create an addressingscheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This company will be using the class C address 192.168.16.0.Remember to start with your largest groups first.


Frederick20 Hosts

Baltimore60 Hosts

LAN Address:

192.168.16.0/25

LAN Address:

192.168.16.192/27LAN Address:

192.168.16.128/26

WAN Address #1:

192.168.16.224/30 WAN Address #2:192.168.16.228/30


.255.240

.232

- .2

39

.0

.127

.191

.128

.223

.192

.224 -

.227

.228 -

.231

.0

18




scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This business will be using the class C address 200.20.20.0.Remember to start with your largest groups first.

MarketingDepartment

50 Hosts

LAN Address:

Department25 Hosts

LAN Address:

MarketingDepartment100 Hosts

LAN Address:

.224

.255

.127

.191

.128

.223

.192

19



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This company will be using the class C address 199.55.70.0.Remember to start with your largest groups first.


LAN Address:

New York

21 Hosts

LAN Address:

115 Hosts 8 Hosts

LAN Address:

LAN Address:

12 Hosts

WAN Address #1:

Boston.0

- .3

.24 - .

27

.8 -

.11

.16 -

.19

.64 - .67

.56 - .59

.48 - .51

.40 - .4

3.32 -

.35

.104 - .107.96 - .99

.88 - .91

.80 - .83

.72 - .75

.112 - .115

.120 - .123

.176 - .179

.224 -

.227

.216 -

.219

.192 - .195

.208 - .21

1

.200 - .203

.184 - .187

.168. - 171

.152 - .155

.136 - .139

.160 - .163 .144 - .147

.128 - .131

.248

- .2

51

.232 -

.235

.240

- .24

3

.4 -

.7

.12

- .15

.20 -

.23

.28 - .

31

.36 - .

39

.44 - .47

.52 - .55

.60 - .63

.68 - .71

.76 - .79.84 - .87.92 - .95

.100 - .103

.108 - .111

.116 - .119

.124 - .127

.132 - .135.140 - .143

.148 - .151.156 - .159

.164 - .167

.172. - 175

.180 - .183

.188 - .191

.196 - .199

.204 - .207

.212 - .2

15 .220

- .223 .22

8 - .2

31

.236

- .23

9

.244

- .24

7

.252

- .2

55

20



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This company will be using the class C address 200.150.70.0.Remember to start with your largest groups first.

New Delhi

LAN Address:

22 Hosts

5 Hosts

LAN Address:

LAN Address:

7 Hosts

LAN Address:

35 Hosts

Serial Address:

Mumbai

12HostsLAN Address:


.0 -

.3

.24 - .

27

.8 -

.11

.16 -

.19

.64 - .67

.56 - .59

.48 - .51

.40 - .4

3.32 -

.35

.104 - .107.96 - .99

.88 - .91

.80 - .83

.72 - .75

.112 - .115

.120 - .123

.176 - .179

.224 -

.227

.216 -

.219

.192 - .195

.208 - .21

1

.200 - .203

.184 - .187

.168. - 171

.152 - .155

.136 - .139

.160 - .163 .144 - .147

.128 - .131

.248

- .2

51

.232 -

.235

.240

- .24

3

.4 -

.7

.12

- .15

.20 -

.23

.28 - .

31

.36 - .

39

.44 - .47

.52 - .55

.60 - .63

.68 - .71

.76 - .79.84 - .87.92 - .95

.100 - .103

.108 - .111

.116 - .119

.124 - .127

.132 - .135.140 - .143

.148 - .151.156 - .159

.164 - .167

.172. - 175

.180 - .183

.188 - .191

.196 - .199

.204 - .207

.212 - .2

15 .220

- .223 .22

8 - .2

31

.236

- .23

9

.244

- .24

7

.252

- .2

55

21



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the circle below, color or shade the sub-subnets used.This company will be using the class C address 210.10.10.0.Remember to start with your largest groups first.LAN Address:

Hong Kong

WAN Address #2:

18 Hosts

LAN Address:

95 Hosts 12 Hosts

LAN Address:

LAN Address:

27 Hosts

WAN Address #1:

Shanghai

Beijing

18 Hosts

Draw the necessary lines and color in the used circle sectionswith different shades to highlight each subnet.

.0

.127

.191

.128

.223

.192

.224 .31.32

.63

.64

.95.96.159

.160

.255

22



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets usedin the circle. This company will be using the class C address 192.168.150.0.Remember to start with your largest groups first.

Vienna15 Hosts

Frankfurt30 Hosts

LAN Address:

LAN Address:

WAN Address #2:

Prague12 Hosts

48 Hosts

LAN Address:

WAN Address #1:

Draw the necessary lines andcolor in the used circle sectionswith different shades to highlighteach subnet.

Venice 23 Hosts

48 Hosts

LAN Address:

WAN Address #3:LAN Address:

.0

.127

.191

.128

.192 .63.64

.255

23



scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets usedin the circle. This company will be using the class C address 195.75.23.0.Remember to start with your largest groups first.

San Juan

LAN Address:

WAN Address #1:

Draw the necessary lines andcolor in the used circle sectionswith different shades to highlighteach subnet.

Kingston

WAN Address #2:

6 Hosts

12 Hosts

LAN Address:

24 Hosts 37 Hosts

LAN Address:

LAN Address:

Guatemala City

San Jose

12 Hosts

LAN Address:

13 Hosts

WAN Address #3

.0

.127.128

.255

Visualizing Subnets Using aVLSM Chart

The VLSM chart is the third method used to visualize the breakdown ofsubnets and addresses into smaller sizes. By shading or coloring in theboxes you can easily break up your subnets without overlapping youraddresses. You can adjust each sub-subnet to the correct size needed.

24

MarketingDepartment

60 Hosts

LAN Address:

220.10.10.0/26

ResearchDepartment

28 Hosts

LAN Address:

220.10.10.64/27

VLSM AddressingVLSM Chart Method

(Sample)Problem 17

Using the network diagram and information given create an addressingscheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe chart. This business will be using the class C address 220.10.10.0.Remember to start with your largest groups first.

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

25

Class C AddressesVLSM Chart 24-30 Bits (4th octet)

26


(Sample)Problem 18

Using the network diagram and information given create an address-ing scheme which utilizes variable-length subnet masks. Show the subnetaddress and CIDR in the boxes below, color or shade the sub-subnets used inthe chart. This company will be using the class C address 192.168.16.0. Re-member to start with your largest groups first.


Frederick20 Hosts

Baltimore60 Hosts

LAN Address:

192.168.16.0/25

LAN Address:

192.168.16.192/27LAN Address:

192.168.16.128/26

WAN Address #1:

192.168.16.224/30 WAN Address #2:192.168.16.228/30

27

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


28


Problem 19Using the network diagram and information given create an

addressing scheme which utilizes variable-length subnet masks. Show thesubnet address and CIDR in the boxes below, color or shade the sub-subnetsused in the chart. This company will be using the class C address 199.55.78.0.Remember to start with your largest groups first.

LAN Address:

Site 250 Hosts

LAN Address:

Site 130 Hosts

WAN Address #1:

LAN Address:

Site 4100 Hosts

Site 310 Hosts

LAN Address:

29

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


30




WAN Address #2:

WAN Address #1:

LAN Address:

Bedford12 Hosts

Richland Hills10 Hosts

LAN Address:

LAN Address:Hurst

60 Hosts

Euless50 Hosts

LAN Address:

Arlington15 Hosts

31

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


32




23 Hosts 15 Hosts

17 Hosts 40 Hosts

35 Hosts 18 Hosts

LAN Address:

12 HostsLAN Address:

WAN Address #2:

WAN Address #1:

WAN Address #1:

WAN Address #1:

33

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


34




LAN Address:

LAN Address:

LAN Address:

WAN Address #3:

Router A

Hagerstown25 Hosts

Router B

Router C

Router D

FrederickSite A

45 Hosts

Middletown10 Hosts

WAN Address #1:

WAN Address #2:

FrederickSite B

23 Hosts

Boonsburo35 Hosts

LAN Address:

35

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


36




LAN Address:

Boston25 Hosts

New York22 Hosts

Virgina34 Hosts

West Virginia11 Hosts

Utah36 Hosts

Maryland25 Hosts

WAN Address #1:

Texas10 Hosts

WAN Address #2:

LAN Address:

WAN Address #3:

LAN Address:

LAN Address:

37

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


38




27 Hosts

12 Hosts

LAN Address:

LAN Address: LAN Address:

WAN Address #1: WAN Address #2:

WAN Address #3:

LAN Address:

8 Hosts5 Hosts 8 Hosts 6 Hosts

18 Hosts

WAN Address #4:

LAN Address:

39

0-127

128-255

0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

16-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255


Practical VLSMProblems

Use the VLSM method of your choice to completethe folowing problems.

.0 - .

3

.24 - .

27

.8 - .

11

.16 -

.19

.64 - .67

.56 - .59

.48 - .51

.40 - .4

3.32

- .35

.104 - .107.96 - .99

.88 - .91

.80 - .83

.72 - .75

.112 - .115

.120 - .123

.176 - .179

.224 -

.227

.216 -

.219

.192 - .195

.208 - .21

1

.200 - .203

.184 - .187

.168. - 171

.152 - .155 .136 - .139

.160 - .163

.144 - .147

.128 - .131

.248

- .2

51

.232

- .23

5

.240

- .24

3

.4 - .

7

.12

- .15

.20 -

.23

.28 - .

31

.36 - .

39

.44 - .47

.52 - .55

.60 - .63

.68 - .71

.76 - .79

.84 - .87.92 - .95

.100 - .103

.108 - .111

.116 - .119

.124 - .127

.132 - .135

.140 - .143.148 - .151

.156 - .159

.164 - .167

.172. - 175

.180 - .183

.188 - .191

.196 - .199

.204 - .207

.212 - .

215.22

0 - .2

23 .228

- .23

1

.236

- .23

9

.244

- .2

47

.252

- .2

55

VLSM

Add

ress

ing

(Sam

ple)

Prob

lem

25

You

are

deve

lopi

ng a

sch

ool n

etw

ork

with

the

clas

s C

add

ress

192

.168

.2.0

/24.

The

re w

ill be

thre

eco

mpu

ter l

abs

with

30

com

pute

rs e

ach

that

nee

d to

be

on d

iffer

ent s

ub-s

ubne

ts.

Forty

eig

ht c

lass

room

s w

ithon

e co

mpu

ter e

ach

that

will

com

pris

e a

sing

le s

ub-s

ubne

t. T

he a

dmin

istra

tive

offic

e an

d gu

idan

ce o

ffice

cont

ain

a to

tal o

f sev

en c

ompu

ters

whi

ch w

ill ne

ed to

be

grou

ped

toge

ther

. P

lan

for f

our m

ore

min

i lab

s w

ithsi

x co

mpu

ters

to e

ach

sub-

subn

etw

ork.

Div

ide

the

netw

ork

usin

g va

riabl

e le

ngth

sub

net m

asks

. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Rem

embe

r to

wor

k fro

m la

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ss19

2.1

68.2

.019

2.1

68.2

.64

192

.168

.2.9

619

2.1

68.2

.12

819

2.1

68.2

.160

192

.168

.2.1

7619

2.1

68.2

.184

192

.168

.2.1

9219

2.1

68.2

.200

Subn

etM

ask

(/X)

/26

/27

/27

/27

/28

/29

/29

/29

/29

Firs

t Usa

ble

Hos

t19

2.1

68.2

.119

2.1

68.2

.65

192

.168

.2.9

719

2.1

68.2

.12

919

2.1

68.2

.161

192

.168

.2.1

7719

2.1

68.2

.185

192

.168

.2.1

9319

2.1

68.2

.201

Last

Usa

ble

Hos

t19

2.1

68.2

.62

192

.168

.2.9

419

2.1

68.2

.12

619

2.1

68.2

.15

819

2.1

68.2

.174

192

.168

.2.1

8219

2.1

68.2

.190

192

.168

.2.1

9819

2.1

68.2

.206

Bro

adca

stA

ddre

ss19

2.1

68.2

.63

192

.168

.2.9

519

2.1

68.2

.12

719

2.1

68.2

.15

919

2.1

68.2

.175

192

.168

.2.1

8319

2.1

68.2

.191

192

.168

.2.1

9919

2.1

68.2

.207

42

43

VLSM

Add

ress

ing

(Sam

ple)

Prob

lem

26

You

are

setti

ng u

p a

smal

l bus

ines

s ne

twor

k w

ith th

e cl

ass

C a

ddre

ss 2

20.5

5.80

.0/2

4. T

he m

arke

ting

divi

sion

will

need

12

com

pute

rs.

Res

earc

h an

d de

velo

pmen

t nee

ds 2

7 co

mpu

ters

. Th

e re

cept

ion

area

will

need

two

com

pute

rs.

Man

agem

ent r

equi

res

19 c

ompu

ters

. D

ivid

e th

e ne

twor

k us

ing

varia

ble

leng

th s

ubne

tm

asks

. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Rem

embe

r to

wor

k fro

m la

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ss2

20.

55

.80.

02

20.

55

.80.

322

20.

55

.80.

642

20.

55

.80.

80

Subn

etM

ask

(/X)

/27

/27

/28

/30

Firs

t Usa

ble

Hos

t2

20.

55

.80.

12

20.

55

.80.

22

0.5

5.8

0.65

22

0.5

5.8

0.81

Last

Usa

ble

Hos

t2

20.

55

.80.

302

20.

55

.80.

622

20.5

5.8

0.7

82

20.

55

.80.

82

Bro

adca

stA

ddre

ss2

20.

55

.80.

312

20.

55

.80.

632

20.

55

.80.

792

20.

55

.80.

83

44

VLSM

Add

ress

ing

Prob

lem

27

You

are

setti

ng u

p a

med

ium

siz

ed n

etw

ork

with

the

clas

s C

add

ress

222

.37.

34.0

/24.

Mar

ketin

g ne

eds

29 c

ompu

ters

. R

esea

rch

and

deve

lopm

ent n

eeds

110

com

pute

rs.

Boo

kkee

ping

will

use

12 c

ompu

ters

.Th

e re

cept

ion

area

will

need

thre

e co

mpu

ters

. M

anag

emen

t req

uire

s 60

com

pute

rs.

Div

ide

the

netw

ork

usin

g va

riabl

e le

ngth

sub

net m

asks

. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Rem

embe

r to

wor

k fro

mla

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

45

VLSM

Add

ress

ing

Prob

lem

28

A s

hipp

ing

com

pany

nee

ds to

set

up

its n

etw

ork

acro

ss s

ever

al lo

catio

ns.

The

Den

ver o

ffice

nee

ds s

ixco

mpu

ters

. Th

e W

aco

offic

e ne

eds

22 c

ompu

ters

. Th

e Fa

rgo

offic

e w

ill ne

ed fi

ve c

ompu

ters

. Th

e W

ANlin

ks b

etw

een

all t

hree

loca

tions

nee

d to

be

incl

uded

in th

e so

lutio

n. U

sing

the

IP a

ddre

ss 1

92.1

68.1

0.0/

24di

vide

the

netw

ork

usin

g VL

SM.

Com

plet

e th

e in

form

atio

n re

quire

d be

low

. R

emem

ber t

o w

ork

from

larg

est

to s

mal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

46

VLSM

Add

ress

ing

Prob

lem

29

A n

ew s

choo

l is

bein

g bu

ilt in

the

loca

l sch

ool d

istri

ct.

It w

ill ha

ve th

ree

com

pute

r lab

s w

ith 2

8co

mpu

ters

eac

h. T

here

will

be 5

8 cl

assr

oom

s w

ith 2

com

pute

rs e

ach

that

nee

d to

be

on o

ne s

ub-s

ubne

t.Th

e of

fice

staf

f and

adm

inis

trato

rs w

ill ne

ed 7

com

pute

rs.

The

guid

ance

and

atte

ndan

ce o

ffice

will

have

5co

mpu

ters

. Th

e sc

hool

has

bee

n gi

ven

the

addr

ess

223.

145.

75.0

/24.

C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Rem

embe

r to

wor

k fro

m la

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

47

VLSM

Add

ress

ing

Prob

lem

30

A lo

cal c

olle

ge is

set

ting

up a

cam

pus

wid

e ne

twor

k. T

he te

chno

logy

win

g w

ill be

on

its o

wn

netw

ork

addr

ess

of 1

92.1

68.2

50.0

/24.

Th

e of

fice

win

g w

ill in

clud

e 15

com

pute

rs.

Ther

e ar

e 2

labs

of 2

0 co

mpu

ters

each

, 2 la

bs o

f 30

com

pute

rs e

ach

and

one

lab

of 3

5 co

mpu

ters

. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Rem

embe

r to

wor

k fro

m la

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

48

VLSM

Add

ress

ing

Prob

lem

31

You

are

setti

ng u

p a

netw

ork

for a

com

pany

in fo

ur lo

catio

ns.

Loca

tion

A ha

s 8

com

pute

rs.

Loca

tion

Bha

s 12

2 co

mpu

ters

. Lo

catio

n C

has

4 c

ompu

ters

. Lo

catio

n D

has

55

com

pute

rs.

Ther

e is

a W

AN

con

nec-

tion

betw

een

all f

our l

ocat

ions

. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w u

sing

the

clas

s C

add

ress

192.

168.

10.0

. R

emem

ber

to w

ork

from

larg

est t

o sm

alle

st.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

49

VLSM

Add

ress

ing

Prob

lem

32

A co

llege

dor

mito

ry is

bei

ng re

mol

ded.

A n

ew n

etw

ork

is b

eing

inst

alle

d. T

here

are

50

dorm

room

sw

ith tw

o dr

ops

each

that

will

be o

n on

e su

b-su

bnet

. Th

e of

fices

will

have

5 d

rops

. Th

e re

cept

ion

desk

will

have

thre

e dr

ops.

A s

mal

l stu

dy h

all w

ill in

clud

e 30

dro

ps.

Usi

ng th

e IP

add

ress

192

.168

.12.

0/24

com

plet

eth

e in

form

atio

n re

quire

d be

low

usi

ng V

LSM

. W

ork

from

larg

est t

o sm

alle

st.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

50

VLSM

Add

ress

ing

Prob

lem

33

You

are

setti

ng u

p a

busi

ness

net

wor

k w

ith th

e cl

ass

C a

ddre

ss 2

19.7

5.16

0.0/

24.

The

mar

ketin

gdi

visi

on w

ill ne

ed 1

9 co

mpu

ters

. R

esea

rch

and

deve

lopm

ent n

eeds

40

com

pute

rs.

The

rece

ptio

n ar

ea w

illne

ed fo

ur c

ompu

ters

. M

anag

emen

t req

uire

s 12

com

pute

rs.

Div

ide

the

netw

ork

usin

g va

riabl

e le

ngth

sub

net

info

rmat

ion.

On

the

oppo

site

pag

e dr

aw a

det

aile

d m

ap o

f thi

s ne

twor

k. I

nclu

de th

e na

me

and

sub-

subn

et IP

addr

esse

s fo

r eac

h br

anch

of t

he n

etw

ork

with

the

subn

et m

ask.

One

rout

er w

ith fo

ur e

ther

net p

orts

will

beus

ed fo

r thi

s ne

twor

k.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etA

ddre

ssSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

51

Prob

lem

33

- Det

aile

d M

apD

raw

a d

etai

led

map

of t

his

netw

ork.

Inc

lude

the

nam

e an

d su

b-su

bnet

IP a

ddre

sses

info

rmat

ion

for e

ach

bran

ch o

f the

net

wor

k, a

nd th

e su

bnet

mas

k.

52

VLSM

Add

ress

ing

Prob

lem

34

A sm

all c

ompa

ny n

eeds

to s

et u

p its

net

wor

k ac

ross

sev

eral

loca

tions

. Th

e N

ew Y

ork

bran

ch o

ffice

need

s 15

com

pute

rs.

The

San

Jos

e of

fice

need

s 66

com

pute

rs.

The

Trin

idad

offi

ce w

ill ne

ed 1

8co

mpu

ters

. Yo

u w

ill ne

ed tw

o W

AN

link

s be

twee

n th

e ro

uter

s. U

sing

the

IP a

ddre

ss 1

95.2

0.5.

0/24

div

ide

the

netw

ork

usin

g V

LSM

. O

n th

e op

posi

te p

age

draw

a d

etai

led

map

of t

his

netw

ork.

Inc

lude

the

nam

e an

d su

b-su

bnet

IP a

ddre

sses

info

rmat

ion

for e

ach

bran

ch o

f the

net

wor

k. L

abel

the

WA

N li

nks

with

the

sam

e in

form

a-tio

n. C

ompl

ete

the

info

rmat

ion

requ

ired

belo

w.

Wor

k fro

m la

rges

t to

smal

lest

.

Subn

et

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Subn

etSu

bnet

Mas

k (/X

)Fi

rst U

sabl

eH

ost

Last

Usa

ble

Hos

tB

road

cast

Add

ress

Prob

lem

34

- Det

aile

d M

apD

raw

a d

etai

led

map

of t

his

netw

ork.

Inc

lude

the

nam

e an

d su

b-su

bnet

IP a

ddre

sses

info

rmat

ion

for e

ach

bran

ch o

f the

net

wor

k.

53

Class A and BVLSM

Problems

Class A AddressesVLSM Chart 8-15 Bits (2nd octet)

Class B AddressesVLSM Chart 16-23 Bits (3rd octet)


10 . 0 . 0 . 0

VLSMwith

Class A and B Addresses

Weve gone over the practical applications of using VLSM on class C addresses. The sameapproach works with class A and B addresses. For example an ISP may have a class Aaddress which it needs to subnet between its customers. Each customer may need to taketheir addresses and subnet them again in order to use them more effectively. The real trick tothis is to remember which octet of the IP address you are working with.

Sample Problem 35Part 1 of 3

Use the Class A address chart to break down the address for different ISP customers. At thisstage of the problem you are creating subnets using the second octet of the IP address.

ISP Addresses 15.0.0.0

56

CustomerName

Number ofAddresses

Address Range(Include subnet & broadcast addresses)

Customer #1

Customer #2

Customer #3

Customer #4

Customer #5

Customer #6

Customer #7

Customer #8

Customer #9

8 million

2 million

2,000,000

1,000,000

500,000

450,000

200,000

130,000

100,000

15.0.0.0 to 15.127.255.255

15.128.0.0 to 15.159.255.255

15.160.0.0 to 15.191.255.255

15.192.0.0 to 15.207.255.255

15.208.0.0 to 15.215.255.255

15.216.0.0 to 15.223.255.255

15.224.0.0 to 15.227.255.255

15.228.0.0 to 15.229.255.255

15.230.0.0 to 15.231.255.255

/9

/11

/11

/12

/13

/13

/14

/15

/15

CIDR

57


0-127

128-255

/14255.252.0.0

262,144 Hosts

/13255.248.0.0

524,288 Hosts

/12255.240.0.0

1,048,576 Hosts

/11255.224.0.0

2,097,152 Hosts

/10255.192.0.0

4,194,304 Hosts

/9255.128.0.0

8,388.608 Hosts

/8255.0.0.0

16,777,216 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

/15255.254.0.0

131,072 Hosts0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

0 - 12 - 34 - 56 - 78 - 9

10 - 1112 - 1314 - 1516 - 1718 - 1920 - 2122 - 2324 - 2526 - 2728 - 2930 - 3132 - 3334 - 3536 - 3738 - 3940 - 4142 - 4344 - 4546 - 4748 - 4950 - 5152 - 5354 - 5556 - 5758 - 5960 - 6162 - 6364 - 6566 - 6768 - 6970 - 7172 - 7374 - 7576 - 7778 - 7980 - 8182 - 8384 - 8586 - 8788 - 8990 - 9192 - 9394 - 9596 - 9798 - 99

100 - 101102 - 103104 - 105106 - 107108 - 109110 - 111112 - 113114 - 115116 - 117118 - 119120 - 121122 - 123124 - 125126 - 127128 - 129130 - 131132 - 133134 - 135136 - 137138 - 139140 - 141142 - 143144 - 145146 - 147148 - 149150 - 151152 - 153154 - 155156 - 157158 - 159160 - 161162 - 163164 - 165166 - 167168 - 169170 - 171172 - 173174 - 175176 - 177178 - 179180 - 181182 - 183184 - 185186 - 187188 - 189190 - 191192 - 193194 - 195196 - 197198 - 199200 - 201202 - 203204 - 205206 - 207208 - 209210 - 211212 - 213214 - 215216 - 217218 - 219220 - 221222 - 223224 - 225226 - 227228 - 229230 - 231232 - 233234 - 235236 - 237238 - 239240 - 241242 - 243244 - 245246 - 247248 - 249250 - 251252 - 253254 - 255

VLSMwith

Class A and B AddressesSample Problem 35

Part 2 of 3

Customer #5 has a total of 524,288 addresses. Use the Class B address chart to breakdown the sub-subnetwork addresses for their different clients. At this stage of the problem youare creating sub-subnets with the third octet of the IP address.


CustomerName

Number ofAddresses


Client #1

Client #2

Client #3

Client #4

Client #5

Client #6

Client #7

Client #8

Client #9

7,500

5,000

4,500

2,000

1,450

1,150

900

750

450

15.208.0.0 to 15.208.31.255

15.208.32.0 to 15.208.63.255

15.208.64.0 to 15.208.95.255

15.208.96.0 to 15.208.103.255

15.208.104.0 to 15.208.111.255

15.208.112.0 to 15.208.119.255

15.208.120.0 to 15.208.123.255

15.208.124.0 to 15.208.127.255

15.208.128.0 to 15.208.129.255

/19

/19

/19

/21

/21

/21

/22

/22

/23

CIDR

58

0-127

128-255


/22255.255.252.01,024 Hosts

/21255.255.248.02,048 Hosts

/20255.255.240.04,096 Hosts

/19255.255.224.08,192 Hosts

/18255.255.192.016,384 Hosts

/17255.255.128.032,768 Hosts

/16255.255.0.0

65,536 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

/23255.255.254.0

512 Hosts0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

0 - 12 - 34 - 56 - 78 - 9

10 - 1112 - 1314 - 1516 - 1718 - 1920 - 2122 - 2324 - 2526 - 2728 - 2930 - 3132 - 3334 - 3536 - 3738 - 3940 - 4142 - 4344 - 4546 - 4748 - 4950 - 5152 - 5354 - 5556 - 5758 - 5960 - 6162 - 6364 - 6566 - 6768 - 6970 - 7172 - 7374 - 7576 - 7778 - 7980 - 8182 - 8384 - 8586 - 8788 - 8990 - 9192 - 9394 - 9596 - 9798 - 99

100 - 101102 - 103104 - 105106 - 107108 - 109110 - 111112 - 113114 - 115116 - 117118 - 119120 - 121122 - 123124 - 125126 - 127128 - 129130 - 131132 - 133134 - 135136 - 137138 - 139140 - 141142 - 143144 - 145146 - 147148 - 149150 - 151152 - 153154 - 155156 - 157158 - 159160 - 161162 - 163164 - 165166 - 167168 - 169170 - 171172 - 173174 - 175176 - 177178 - 179180 - 181182 - 183184 - 185186 - 187188 - 189190 - 191192 - 193194 - 195196 - 197198 - 199200 - 201202 - 203204 - 205206 - 207208 - 209210 - 211212 - 213214 - 215216 - 217218 - 219220 - 221222 - 223224 - 225226 - 227228 - 229230 - 231232 - 233234 - 235236 - 237238 - 239240 - 241242 - 243244 - 245246 - 247248 - 249250 - 251252 - 253254 - 255

59

VLSMwith

Class A and B AddressesSample Problem 35

Part 3 of 3

Client #8 has a total of 1,024 addresses. Use the Class C address chart to break down thesub-subnetwork addresses for their different branch offices. At this stage of the problem youare creating sub-subnets with the fourth octet of the IP address.


CustomerName

Number ofAddresses


Branch #1

Branch #2

Branch #3

Branch #4

Branch #5

Branch #6

Branch #7

Branch #8

Branch #9

100

55

25

6

4

2

2

2

2

15.208.124.0 to 15.208.124.127

15.208.124.128 to 15.208.124.191

15.208.124.192 to 15.208.124.223

15.208.124.224 to 15.208.124.231

15.208.124.232 to 15.208.124.239

15.208.124.240 to 15.208.124.243

15.208.124.244 to 15.208.124.247

15.208.124.248 to 15.208.124.251

15.208.124.252 to 15.208.124.255

/25

/26

/27

/29

/29

/30

/30

/30

/30

CIDR

60

0-127

128-255


0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

61

VLSMwith

Class A and B AddressesProblem 36Part 1 of 3

The school system you are working for is using the private address of 172.32.0.0 to subnet theentire district. Use the Class B address chart to break down the sub-subnetwork addressesfor the different schools and offices.

At this stage of the problem you are creating sub-subnets with the third octet of the IP address.Remember which octet of the IP address you are working in.

School System Address 172.32.0.0

CustomerName

Number ofAddresses


North High

South High

North Middle

South Middle

Central Elem.

Southern Elem.

Eastern Elem.

Central Office

Western Elem.

2,400

2,000

1,200

1,000

550

475

450

400

300

CIDR

62

0-127

128-255


/22255.255.252.01,024 Hosts

/21255.255.248.02,048 Hosts

/20255.255.240.04,096 Hosts

/19255.255.224.08,192 Hosts

/18255.255.192.016,384 Hosts

/17255.255.128.032,768 Hosts

/16255.255.0.0

65,536 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

/23255.255.254.0

512 Hosts0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

0 - 12 - 34 - 56 - 78 - 9

10 - 1112 - 1314 - 1516 - 1718 - 1920 - 2122 - 2324 - 2526 - 2728 - 2930 - 3132 - 3334 - 3536 - 3738 - 39

48 - 4950 - 5152 - 5354 - 5556 - 5758 - 5960 - 6162 - 6364 - 6566 - 6768 - 6970 - 7172 - 7374 - 7576 - 7778 - 7980 - 8182 - 8384 - 8586 - 8788 - 8990 - 9192 - 9394 - 9596 - 9798 - 99

100 - 101102 - 103104 - 105106 - 107108 - 109110 - 111112 - 113114 - 115116 - 117118 - 119120 - 121122 - 123124 - 125126 - 127128 - 129130 - 131132 - 133134 - 135136 - 137138 - 139140 - 141142 - 143144 - 145146 - 147148 - 149150 - 151152 - 153154 - 155156 - 157158 - 159160 - 161162 - 163164 - 165166 - 167168 - 169170 - 171172 - 173174 - 175176 - 177178 - 179180 - 181182 - 183184 - 185186 - 187188 - 189190 - 191192 - 193194 - 195196 - 197198 - 199200 - 201202 - 203204 - 205206 - 207208 - 209210 - 211212 - 213214 - 215216 - 217218 - 219220 - 221222 - 223224 - 225226 - 227228 - 229230 - 231232 - 233234 - 235236 - 237238 - 239240 - 241242 - 243244 - 245246 - 247248 - 249250 - 251252 - 253254 - 255

63

40 - 4142 - 4344 - 4546 - 47

VLSMwith


Eastern Elementary has been given 512 hosts, with the address range of 172.32.42.0 / 21(255.255.248.0).

Based on the information below supply the required address ranges and subnet masks foreach school area. Use the Class C address chart to break down the sub-subnetworks.

Hint: Another way to look at this problem is to see that with the third octet range of 42 to 43 youhave access to 2 groups of 255 addresses (172.32.42.0 and 172.32.43.0). Think in terms ofhaving two Class C VLSM charts.

Eastern Elementary SchoolAddress Range 172.32.42.0 to 172.32.43.255

CustomerName

Number ofAddresses


250

45

40

25

12

CIDR

Students

Printers

Staff

Network Devices

Administrative

64

0-127

128-255


0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

65

VLSMwith


South High in part 1 of this problem has been given 2,048 hosts, with the address range of172.32.16.0 / 21 (255.255.248.0).

Based on the information below supply the required address ranges and subnet masks foreach school area. Use both the Class B and Class C address charts to break down the sub-subnetwork addresses for the different areas of the network.

Hint:With this problem you are creating sub-subnets with both the third and fourth octets of the IPaddress. You may need to use the Class B VLSM chart for the Students addressinginformation. All the other addresses will be using the Class C VLSM chart. Another way tolook at this problem is to see that with the third octect range of 16 to 23 you have access to 8groups of 255 addresses or eight Class C VLSM charts.

South High SchoolAddress Range 172.32.16.0 to 172.32.23.255

CustomerName

Number ofAddresses


1,000

250

200

150

50

CIDR

Students

Network Devices

Printers

Staff

Administrative

66

0-127

128-255


0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

/30255.255.255.252

4 Hosts

/29255.255.255.248

8 Hosts

/28255.255.255.240

16 Hosts

/27255.255.255.224

32 Hosts

/26255.255.255.192

64 Hosts

/25255.255.255.128

128 Hosts

/24255.255.255.0

256 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

67

68

CustomerName

Number ofAddresses


Moskva

New York

St. Petersburg

London

Ekaterinoburg

Munchen

Napoli

Birmingham

Rotterdam

3,050,000

1,540,000

1,075,000

975,000

525,000

450,000

150,000

130,000

95,000

CIDR

VLSMwith


The company you are working for is using the IP address 110.0.0.0 sub-subneted for multipleoffices around the world. Use the Class A address chart to break down the sub-subnetworkaddresses for the different offices.

At this stage of the problem you are creating sub-subnets with the third octet of the IP address.Remember which octet of the IP address you are working in.

Company Address 110.0.0.0

69


0-127

128-255

/14255.252.0.0

262,144 Hosts

/13255.248.0.0

524,288 Hosts

/12255.240.0.0

1,048,576 Hosts

/11255.224.0.0

2,097,152 Hosts

/10255.192.0.0

4,194,304 Hosts

/9255.128.0.0

8,388.608 Hosts

/8255.0.0.0

16,777,216 Hosts

0-7

8-15

16-23

24-31

32-39

40-47

48-55

56-63

64-71

72-79

80-87

88-95

96-103

104-111

112-119

120-127

128-135

136-143

144-151

152-159

160-167

168-175

176-183

184-191

192-199

200-207

208-215

216-223

224-231

232-239

240-247

248-255

0-15

16-31

32-47

48-63

64-79

80-95

96-111

112-127

128-143

144-159

160-175

176-191

192-207

208-223

224-239

240-255

0-63

64-127

128-191

192-255

0 - 255

/15255.254.0.0

131,072 Hosts0-34-78-11

12-1516-1920-2324-2728-3132-3536-3940-4344-4748-5152-5556-5960-6364-6768-7172-7576-7980-8384-8788-9192-9596-99

100-103104-107108-111112-115116-119120-123124-127128-131132-135136-139140-143144-147148-151152-155156-159160-163164-167168-171172-175176-179180-183184-187188-191192-195196-199200-203204-207208-211212-215216-219220-223224-227228-231232-235236-239240-243244-247248-251252-255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

0 - 12 - 34 - 56 - 78 - 9

10 - 1112 - 1314 - 1516 - 1718 - 1920 - 2122 - 2324 - 2526 - 2728 - 2930 - 3132 - 3334 - 3536 - 3738 - 3940 - 4142 - 4344 - 4546 - 4748 - 4950 - 5152 - 5354 - 5556 - 5758 - 5960 - 6162 - 6364 - 6566 - 6768 - 6970 - 7172 - 7374 - 7576 - 7778 - 7980 - 8182 - 8384 - 8586 - 8788 - 8990 - 9192 - 9394 - 9596 - 9798 - 99

100 - 101102 - 103104 - 105106 - 107108 - 109110 - 111112 - 113114 - 115116 - 117118 - 119120 - 121122 - 123124 - 125126 - 127128 - 129130 - 131132 - 133134 - 135136 - 137138 - 139140 - 141142 - 143144 - 145146 - 147148 - 149150 - 151152 - 153154 - 155156 - 157158 - 159160 - 161162 - 163164 - 165166 - 167168 - 169170 - 171172 - 173174 - 175176 - 177178 - 179180 - 181182 - 183184 - 185186 - 187188 - 189190 - 191192 - 193194 - 195196 - 197198 - 199200 - 201202 - 203204 - 205206 - 207208 - 209210 - 211212 - 213214 - 215216 - 217218 - 219220 - 221222 - 223224 - 225226 - 227228 - 229230 - 231232 - 233234 - 235236 - 237238 - 239240 - 241242 - 243244 - 245246 - 247248 - 249250 - 251252 - 253254 - 255

70

VLSMwith

Class A and B Addresses Problem 37Part 2 of 3

London in part 1 of this problem has been given 1,048,576 hosts, with the address range of110.128.0.0 to 110.143.255.255 /12 (255.240.0.0).

Based on the information below supply the required address ranges and subnet masks foreach office. Use the Class B address chart to break down the sub-subnetwork addresses forthe different areas of the network.

LondonAddress Range 110.128.0.0 to 110.143.255.255

CustomerName

Number ofAddresses


Office #1

Office #2

Office #3

Office #4

Office #5

vlsm work book

Documents

class c address

class b

configurethe subnet

variablelength subnet

class d

default subnet masksclass

classful subnetting

ip address classesclass