101010010001111100

1011100101011100101100011101001101111010001101000001010010110010100101010110011111110101010001011101001101010011001010010101010101010100011001001010100101100011010110001101011010100001011001010100110100101001001.0172.16.1.0 192.168.10.0

010

10.250.1.0172.31.15.0

192.168.10.96192.168.10.126

Version 1.0

VLSMWorkbook

Variable-Length Subnet Mask

Version 1.0

Instructor’s Edition

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 don’t you maywant to consider completing the IP Addressing and Subnetting Workbook.

Produced by: Robb Jonesjonesr@careertech.net

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.

Instructors (and anyone else for that matter) please do not post the Instructors version on public websites.When you do this your giving everyone else worldwide the answers. Yes, students look for answers this way.

It also discourages others; myself included, from posting high quality materials.

0

255

/24255.255.255.0

256 Hosts1 Subnet

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 Cisco, OSPF, Dual IS-IS, BGP-4, and EIGRP.You need to configure your router for Variable Length Subnet Masking bysetting up one of these protocols. Then configure the subnet masks of thevarious interfaces in the IP address interface sub-command. To usesupernet you must also configure IP classless routes.

The Box Method

The box method is the simplest way to visualize the breakdown of arange of addresses into smaller different sized subnets.

1

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

0

255127

128

0

255127

128

6364 192

191

0

255127

128

6364 192

191

32

31

95

96159

223

224

160

/25255.255.255.128

128 Hosts2 Subnets

/26255.255.255.192

64 Hosts4 Subnets

/27255.255.255.224

32 Hosts8 Subnets

2

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

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

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

3

0

255127

128

6364 192

191

32

31

95

96159

223

224

160

1516 48

47

79 11180 112

0 12832 160

15 47

143 175176144

240208239207

39 175167135 1437

11 4335 171163131 1393

27 5951 187179147 15519

31 6355 191183151 15923

75 10799 235227195 20367

79 111103 239321199 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

0 12832 160

15 4739 175167135 1437

31 6355 191183151 15923

79 111103 239321199 20771

95 127119 255247215 22387

408 136 168

16 14448 1765624 152 184

64 19296 22410472 200 232

80 208112 24012088 216 248

/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,You can use these squares in anycombination to fit your addressingneeds.

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

VLSM Addressing(Sample)

Problem 1Using the network diagram and information given create an addressing

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 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

255127

128

6364

95

96

4

VLSM Addressing(Sample)

Problem 2Using the network diagram and information given create an addressing

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 192.168.16.0.Remember 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

239321

224 232

228

240

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

5

6

VLSM Addressing

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

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 190.10.10.0.Remember to start with your largest groups first.

Dallas.60 Hosts

Ft. Worth25 Hosts

LAN Address:

LAN Address:

WAN Address #1:

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

0

255

128

6364

95

96

192.10.10.0/26

192.10.10.96/30

192.10.10.64/27

99

103 111

127

104

100

112

VLSM Addressing

Problem 4Using the network diagram and information given create an addressing

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 220.108.38.0.Remember 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:

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

7

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 239321199 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

220.108.38.224/30

220.108.38.128/26

220.108.38.228/30

220.108.38.192/27

220.108.38.0/25

8

VLSM Addressing

Problem 5Using the network diagram and information given create an addressing

scheme which utilizes variable-length subnet masks. Show the subnetaddress and subnet mask in the boxes below, color or shade the sub-subnets used in the box. This company will be using the class C address192.168.10.0. Remember to start with your largest groups first.

New York115 Hosts

Fargo23 Hosts

LAN Address:

LAN Address:

WAN Address #2:

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

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 239321199 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

192.168.10.240/30

192.168.10.128/26

192.168.10.192/27

192.168.10.244/30

192.168.10.0/25

192.168.10.224/28

VLSM Addressing

Problem 6Using the network diagram and information given create an addressing

scheme which utilizes variable-length subnet masks. Show the subnetaddress and subnet mask in the boxes below, color or shade the sub-subnets used in the box. This company will be using the class C address222.10.150.0. 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 sub-subnet.

9

London

WAN Address #2:

6 Hosts

12 Hosts

LAN Address:

24 Hosts 37 Hosts

LAN Address:

LAN Address:

0

255

111

128

6364 192

191

32

31

95

96159

223

224

160

222.10.150.120/30 222.10.150.124/30

222.10.150.112/29

222.10.150.0/26

222.10.150.64/27

222.10.150.96/28

123

127119

112 120

124

10

VLSM Addressing

Problem 7Using the network diagram and information given create an addressing

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.

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

Boston

LAN Address:

6 Hosts

12 Hosts

LAN Address:

LAN Address:

14 Hosts

LAN Address:

25 Hosts

0

255127

128

6364 192

191

200.150.70.0/27

200.150.70.32/28

200.150.70.64/29

200.150.70.48/28

32

4847

71

31

VLSM Addressing

Problem 8Using the network diagram and information given create an addressing

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:

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

11

London

WAN Address #1:

18 Hosts

LAN Address:

95 Hosts 12 Hosts

LAN Address:

LAN Address:

0

255

34 Hosts

192.168.24.240/30

192.168.24.224/28

192.168.24.0/25

192.168.24.192/27

192.168.24.128/26

127

128

191192

223

224

239

243

240

VLSM

Add

ress

ing

(Sam

ple)

Prob

lem

9Yo

u ar

e de

velo

ping

a s

choo

l net

wor

k w

ith th

e cl

ass

C a

ddre

ss 1

92.1

68.2

.0/2

4. T

here

will

be th

ree

com

pute

r lab

s w

ith 3

0 co

mpu

ters

eac

h th

at n

eed

to b

e on

diff

eren

t sub

-sub

nets

. Fo

rty e

ight

cla

ssro

oms

with

one

com

pute

r eac

h th

at w

ill co

mpr

ise

a si

ngle

sub

-sub

net.

The

adm

inis

trativ

e of

fice

and

guid

ance

offi

ceco

ntai

n a

tota

l of s

even

com

pute

rs w

hich

will

need

to b

e gr

oupe

d to

geth

er.

Pla

n fo

r fou

r mor

e m

ini l

abs

with

six

com

pute

rs to

eac

h su

b-su

bnet

wor

k. D

ivid

e th

e ne

twor

k us

ing

varia

ble

leng

th s

ubne

t mas

ks.

Com

plet

eth

e in

form

atio

n re

quire

d be

low

. R

emem

ber t

o 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

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

12

13

VLSM

Add

ress

ing

(Sam

ple)

Prob

lem

10

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

20.5

5.8

0.8

0

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

0.8

1

Last

Usa

ble

Hos

t2

20.

55

.80.

302

20.

55

.80.

622

20.5

5.8

0.7

82

20.5

5.8

0.8

2

Bro

adca

stA

ddre

ss2

20.

55

.80.

312

20.

55

.80.

632

20.

55

.80.

792

20.5

5.8

0.8

3

14

VLSM

Add

ress

ing

Prob

lem

11

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

ss2

22

.37.

34.0

22

2.3

7.34

.12

82

22

.37.

34.1

922

22

.37.

34.2

24

22

2.3

7.34

.240

Subn

etM

ask

(/X)

/25

/26

/27

/28

/29

Firs

t Usa

ble

Hos

t2

22

.37.

34.1

22

2.3

7.34

.12

92

22

.37.

34.1

932

22

.37.

34.2

25

22

2.3

7.34

.241

Last

Usa

ble

Hos

t2

22

.37.

34.1

26

22

2.3

7.34

.190

22

2.3

7.34

.22

22

22

.37.

34.2

382

22

.37.

34.2

46

Bro

adca

stA

ddre

ss2

22

.37.

34.1

27

22

2.3

7.34

.191

22

2.3

7.34

.22

32

22

.37.

34.2

392

22

.37.

34.2

47

15

VLSM

Add

ress

ing

Prob

lem

12

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

ss19

2.1

68.1

0.0

192

.168

.10.3

219

2.1

68.1

0.4

019

2.1

68.1

0.4

819

2.1

68.1

0.5

2

Subn

etM

ask

(/X)

/27

/29

/29

/30

/30

Firs

t Usa

ble

Hos

t19

2.1

68.1

0.1

192

.168

.10.3

319

2.1

68.1

0.4

119

2.1

68.1

0.4

919

2.1

68.1

0.5

3

Last

Usa

ble

Hos

t19

2.1

68.1

0.3

019

2.1

68.1

0.3

819

2.1

68.1

0.4

619

2.1

68.1

0.5

019

2.1

68.1

0.5

4

Bro

adca

stA

ddre

ss19

2.1

68.1

0.3

119

2.1

68.1

0.3

919

2.1

68.1

0.4

719

2.1

68.1

0.5

119

2.1

68.1

0.5

5

16

VLSM

Add

ress

ing

Prob

lem

13

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

. S

etup

the

rem

aini

ng a

ddre

ssin

g in

to o

ne s

ub-s

ubne

t for

futu

re e

xpan

sion

. Th

e sc

hool

has

bee

ngi

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

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

ss2

23.

145

.75

.02

23.

145

.75

.12

82

23.

145

.75

.160

22

3.14

5.7

5.1

922

23.

145

.75

.22

42

23.

145

.75

.240

22

3.14

5.7

5.2

48

Subn

etM

ask

(/X)

/25

/27

/27

/27

/28

/29

/29

Firs

t Usa

ble

Hos

t2

23.

145

.75

.12

23.

145

.75

.12

92

23.

145

.75

.161

22

3.14

5.7

5.1

932

23.

145

.75

.22

52

23.

145

.75

.241

22

3.14

5.7

5.2

49

Last

Usa

ble

Hos

t2

23.

145

.75

.12

62

23.

145

.75

.15

82

23.

145

.75

.190

22

3.14

5.7

5.2

22

22

3.14

5.7

5.2

382

23.

145

.75

.246

22

3.14

5.7

5.2

54

Bro

adca

stA

ddre

ss2

23.

145

.75

.12

72

23.

145

.75

.15

92

23.

145

.75

.191

22

3.14

5.7

5.2

23

22

3.14

5.7

5.2

392

23.

145

.75

.247

22

3.14

5.7

5.2

55

17

VLSM

Add

ress

ing

Prob

lem

14

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

ss19

2.1

68.2

50.

092

.168

.25

0.64

92.1

68.2

50.

9692

.168

.25

0.12

892

.168

.25

0.16

092

.168

.25

0.19

2

Subn

etM

ask

(/X)

/26

/27

/27

/27

/27

/27

Firs

t Usa

ble

Hos

t92

.168

.25

0.1

92.1

68.2

50.

6592

.168

.25

0.97

92.1

68.2

50.

129

92.1

68.2

50.

161

92.1

68.2

50.

193

Last

Usa

ble

Hos

t92

.168

.25

0.62

92.1

68.2

50.

9492

.168

.25

0.12

692

.168

.25

0.15

892

.168

.25

0.19

092

.168

.25

0.222

Bro

adca

stA

ddre

ss92

.168

.25

0.63

92.1

68.2

50.

9592

.168

.25

0.12

792

.168

.25

0.15

992

.168

.25

0.19

192

.168

.25

0.2

23

18

VLSM

Add

ress

ing

Prob

lem

15

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

ss19

2.1

68.1

0.0

192

.168

.10.1

28

192

.168

.10.

192

192

.168

.10.2

08

192

.168

.10.2

1619

2.1

68.1

0.2

20

192

.168

.10.

22

4

Subn

etM

ask

(/X)

/25

/26

/28

/29

/30

/30

/30

Firs

t Usa

ble

Hos

t19

2.1

68.1

0.1

192

.168

.10.

129

192

.168

.10.1

9319

2.1

68.1

0.2

0919

2.1

68.1

0.2

1719

2.1

68.1

0.2

21

192

.168

.10.

22

5

Last

Usa

ble

Hos

t19

2.1

68.1

0.1

26

192

.168

.10.1

9019

2.1

68.1

0.2

06

192

.168

.10.2

1419

2.1

68.1

0.2

1819

2.1

68.1

0.2

22

192

.168

.10.

22

6

Bro

adca

stA

ddre

ss19

2.1

68.1

0.1

27

192

.168

.10.1

9119

2.1

68.1

0.2

07

192

.168

.10.

215

192

.168

.10.

219

192

.168

.10.

22

319

2.1

68.1

0.2

27

19

VLSM

Add

ress

ing

Prob

lem

16

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

ss19

2.1

68.1

2.0

192

.168

.12

.12

819

2.1

68.1

2.1

6019

2.1

68.1

2.1

68

Subn

etM

ask

(/X)

/25

/27

/29

/29

Firs

t Usa

ble

Hos

t19

2.1

68.1

2.1

192

.168

.12

.12

919

2.1

68.1

2.1

6119

2.1

68.1

2.1

69

Last

Usa

ble

Hos

t19

2.1

68.1

2.1

26

192

.168

.12

.15

819

2.1

68.1

2.1

6619

2.1

68.1

2.1

74

Bro

adca

stA

ddre

ss19

2.1

68.1

2.1

27

192

.168

.12

.15

919

2.1

68.1

2.1

6719

2.1

68.1

2.1

75

20

VLSM

Add

ress

ing

Prob

lem

17

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

mas

ks.

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 su

b-su

bnet

IP a

ddre

sses

for

each

bra

nch

of th

e ne

twor

k w

ith th

e su

bnet

mas

k. O

ne ro

uter

with

four

eth

erne

t por

ts w

ill be

use

d fo

r thi

sne

twor

k.

Subn

et

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

Subn

etA

ddre

ss2

19.7

5.1

60.0

219

.75

.160

.64

219

.75

.160

.96

219

.75

.160

.112

Subn

etM

ask

(/X)

/26

/27

/28

/29

Firs

t Usa

ble

Hos

t2

19.7

5.1

60.1

219

.75

.160

.65

219

.75

.160

.97

219

.75

.160

.113

Last

Usa

ble

Hos

t2

19.7

5.1

60.6

22

19.7

5.1

60.9

42

19.7

5.1

60.1

102

19.7

5.1

60.1

18

Bro

adca

stA

ddre

ss2

19.7

5.1

60.6

32

19.7

5.1

60.9

52

19.7

5.1

60.1

112

19.7

5.1

60.1

19

21

Prob

lem

17

- Det

aile

d M

ap

Res

earc

h &

Dev

elop

men

t40

Com

pute

rs2

19.7

5.1

60 t

o .6

325

5.2

55

.25

5.1

92M

arke

ting

19 C

ompu

ters

219

.75

.160

. 64

to .9

525

5.2

55

.25

5.2

24

Rec

epti

on4

Com

pute

rs2

19.7

5.1

60.1

12 t

o .1

1925

5.2

55

.25

5.2

48M

anag

emen

t12

Com

pute

rs2

19.7

5.1

60.9

6 to

.111

25

5.2

55

.25

5.2

40

22

VLSM

Add

ress

ing

Prob

lem

18

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

. Th

e W

AN

link

s be

twee

n al

l thr

ee lo

catio

ns n

eed

to b

e in

clud

ed.

Usi

ng th

e IP

add

ress

195.

20.5

.0/2

4 di

vide

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.

Incl

ude

the

sub-

subn

et IP

add

ress

es fo

r eac

h br

anch

of t

he n

etw

ork

with

the

subn

et m

ask.

Lab

el th

e W

ANlin

ks w

ith th

e sa

me

info

rmat

ion.

Com

plet

e th

e in

form

atio

n re

quire

d be

low

. 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

ss19

5.2

0.5

.019

5.2

0.5

.12

819

5.2

0.5

.160

195

.20.

5.1

9219

5.2

0.5

.196

Subn

etM

ask

(/X)

/25

/27

/27

/30

/30

Firs

t Usa

ble

Hos

t19

5.2

0.5

.119

5.2

0.5

.129

195

.20.

5.1

6119

5.2

0.5

.193

195

.20.

5.1

97

Last

Usa

ble

Hos

t19

5.2

0.5

.12

619

5.2

0.5

.15

819

5.2

0.5

.190

195

.20.

5.1

9419

5.2

0.5

.198

Bro

adca

stA

ddre

ss19

5.2

0.5

.12

719

5.2

0.5

.15

919

5.2

0.5

.191

195

.20.

5.1

9519

5.2

0.5

.199

Prob

lem

18

- Det

aile

d M

ap

23

66 C

ompu

ters

195

.20.

5.0

to

.12

725

5.2

55

.25

5.1

28

Rec

epti

on4

Com

pute

rs19

5.2

0.5

.160

to

.191

25

5.2

55

.25

5.2

24

Man

agem

ent

12 C

ompu

ters

195

.20.

5.1

28

to .1

59

25

5.2

55

.25

5.2

24

New

Yor

kTr

inid

adS

an J

ose 19

5.2

0.5

.192

to

.195

25

5.2

55

.25

5.2

52

195

.20.

5.1

96 t

o .1

9925

5.2

55

.25

5.2

52

24

Class A Addressing Guide# of Bits

Borrowed23456789

10111213141516171819202122

SubnetMask

255.192.0.0255.224.0.0255.240.0.0255.248.0.0255.252.0.0255.254.0.0255.255.0.0

255.255.128.0255.255.192.0255.255.224.0255.255.240.0255.255.248.0255.255.252.0255.255.254.0255.255.255.0

255.255.255.128255.255.255.192255.255.255.224255.255.255.240255.255.255.248255.255.255.252

Total # ofSubnets

48163264

128256512

1,0242,0484,0968,192

16,38432,76865,536

131,072262,144524,288

1,048,5762,097,1524,194,304

Usable # ofSubnets

26143062

126254510

1,0222,0464,0948,190

16,38232,76665,534

131,070262,142524,286

1,048,5742,097,1504,194,302

Total # ofHosts

4,194,3042,097,1521,048,576524,288262,144131,07265,53632,76816,3848,1924,0962,0481,02451225612864321684

Usable # ofHosts

4,194,3022,097,1501,048,574524,286262,142131,07065,53432,76616,3828,1904,0942,0461,02251025412662301462

Class B Addressing Guide# of Bits

Borrowed23456789

1011121314

SubnetMask

255.255.192.0255.255.224.0255.255.240.0255.255.248.0255.255.252.0255.255.254.0255.255.255.0

255.255.255.128255.255.255.192255.255.255.224255.255.255.240255.255.255.248255.255.255.252

Total # ofSubnets

48163264

128256512

1,0242,0484,0968,192

16,384

Usable # ofSubnets

26143062

126254510

1,0222,0464,0948,190

16,382

Total # ofHosts16,3848,1924,0962,0481,02451225612864321684

Usable # ofHosts16,3828,1904,0942,0461,02251025412662301462

Class C Addressing Guide# of Bits

Borrowed23456

SubnetMask

255.255.255.192255.255.255.224255.255.255.240255.255.255.248255.255.255.252

Total # ofSubnets

48163264

Usable # ofSubnets

26143062

Total # ofHosts

64321684

Usable # ofHosts

62301462

0-127

128-255

0-31

32-63

64-95

96-127

128-159

160-191

192-223

224-255

Inside Cover

VLSM Chart 24-30 Bits

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

0-127