Solved subnetting problems In IP addressingSolved subnetting problems In IP addressing

and subnetting workbookand subnetting workbook

Version 1.1Version 1.1

ByBy

Muhedin Abdullahi MohamedMuhedin Abdullahi Mohamed

muhudin99@hotmail.commuhudin99@hotmail.com

Currently a postgraduate student inCurrently a postgraduate student in

Univeristi Teknologi MalaysiaUniveristi Teknologi Malaysia

September 2009September 2009

The workbook is available at:The workbook is available at:

http://www.scribd.chttp://www.scribd.com/doc/202468om/doc/20246803/IP-Addressing-Sub-03/IP-Addressing-Sub-Netting-WorkbNetting-Workbook ook 

When asked a subnetting problem, you can be presented with several pieces of When asked a subnetting problem, you can be presented with several pieces of 

information information that describe the situation. Githat describe the situation. Given that informven that information, it will be up to youation, it will be up to you

to figure out the remaining pieces of information to solve the problem. In thisto figure out the remaining pieces of information to solve the problem. In this

document I will present solutions to document I will present solutions to problemproblems in s in IP addressing and subnettingIP addressing and subnetting

work book work book v1.1 which v1.1 which was producewas produced byd by Robb JonesRobb Jones. . In the In the first parfirst part of t of thethe

workbook, the types of information that you must be able to identify are asworkbook, the types of information that you must be able to identify are as

follows:follows:

Information Information required required ValueValue

Address classAddress class

Default subnet mask Default subnet mask 

Custom subnet mask Custom subnet mask 

Total number of subnetsTotal number of subnets

Number of usable subnetsNumber of usable subnets

Total number of host addressesTotal number of host addresses

Number of usable addressesNumber of usable addresses

Number of bits borrowedNumber of bits borrowed

Let us now commLet us now commence solving the proence solving the problems skipping thoblems skipping those that se that were alreadywere already

solved solved as examas examples in ples in the worthe workbook.kbook.

Part1Part1

Problem4Problem411::

In this problem, the following data is given :In this problem, the following data is given :

Number Number of needeof needed usable d usable subnets: subnets: 66

Number Number of of needed needed usable usable hosts: hosts: 3030

Network Address :Network Address : 210.100.56.0210.100.56.0

For this For this problem problem the solution the solution isis

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.224255.255.255.224

Total number of subnetsTotal number of subnets 88

Number of usable subnetsNumber of usable subnets 66

Total number of host addressesTotal number of host addresses 3232

Number of usable addressesNumber of usable addresses 3030

Number of bits borrowedNumber of bits borrowed 33

Problem5:Problem5:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 66

11Problems 1, 2 and 3 Problems 1, 2 and 3 are solved in the work book as are solved in the work book as examples.examples.

Number of needed usable hosts:Number of needed usable hosts: 3030

Network Address:Network Address: 195.85.8.0195.85.8.0

For this problem the solution isFor this problem the solution is

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.224255.255.255.224

Total number of subnetsTotal number of subnets 88

Number of usable subnetsNumber of usable subnets 66

Total number of host addressesTotal number of host addresses 3232

Number of usable addressesNumber of usable addresses 3030

Number of bits borrowedNumber of bits borrowed 33

Problem6:Problem6:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 126126

Number of needed usable hosts:Number of needed usable hosts: 131070131070

Network Address:Network Address: 118.0.0.0118.0.0.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class AA

Default subnet maskDefault subnet mask 255.0.0.0255.0.0.0

Custom subnet maskCustom subnet mask 255.254.0.0255.254.0.0

Total number of subnetsTotal number of subnets 128128

Number of usable subnetsNumber of usable subnets 126126

Total number of host addressesTotal number of host addresses 131072131072

Number of usable addressesNumber of usable addresses 131070131070

Number of bits borrowedNumber of bits borrowed 77

Problem7:Problem7:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 20002000

Number of needed usable hosts:Number of needed usable hosts: 1515

Network Address:Network Address: 178.100.0.0178.100.0.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class BB

Default subnet maskDefault subnet mask 255.255.0.0255.255.0.0

Custom subnet maskCustom subnet mask 255.255.255.224255.255.255.224

Total number of subnetsTotal number of subnets 20482048

Number of usable subnetsNumber of usable subnets 20462046

Total number of host addressesTotal number of host addresses 3232

Number of usable addressesNumber of usable addresses 3030

Number of bits borrowedNumber of bits borrowed 1010

Problem8:Problem8:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 11

Number of needed usable hosts:Number of needed usable hosts: 4545

Network Address:Network Address: 200.175.14.0200.175.14.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.192255.255.255.192

Total number of subnetsTotal number of subnets 44

Number of usable subnetsNumber of usable subnets 22

Total number of host addressesTotal number of host addresses 6464

Number of usable addressesNumber of usable addresses 6262

Number of bits borrowedNumber of bits borrowed 22

Problem9:Problem9:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 6060

Number of needed usable hosts:Number of needed usable hosts: 10001000

Network Address:Network Address: 128.77.0.0128.77.0.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class BB

Default subnet maskDefault subnet mask 255.255.0.0255.255.0.0

Custom subnet maskCustom subnet mask 255.255.252.0255.255.252.0

Total number of subnetsTotal number of subnets 6464

Number of usable subnetsNumber of usable subnets 6262

Total number of host addressesTotal number of host addresses 10241024

Number of usable addressesNumber of usable addresses 10221022

Number of bits borrowedNumber of bits borrowed 66

Problem10:Problem10:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable hosts:Number of needed usable hosts: 6060

Network Address:Network Address: 198.100.10.0198.100.10.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.192255.255.255.192

Total number of subnetsTotal number of subnets 44

Number of usable subnetsNumber of usable subnets 22

Total number of host addressesTotal number of host addresses 6464

Number of usable addressesNumber of usable addresses 6262

Number of bits borrowedNumber of bits borrowed 22

Problem11:Problem11:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 250250

Network Address:Network Address: 101.0.0.0101.0.0.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class AA

Default subnet maskDefault subnet mask 255.0.0.0255.0.0.0

Custom subnet maskCustom subnet mask 255.255.0.0255.255.0.0

Total number of subnetsTotal number of subnets 256256

Number of usable subnetsNumber of usable subnets 254254

Total number of host addressesTotal number of host addresses 6553665536

Number of usable addressesNumber of usable addresses 6553465534

Number of bits borrowedNumber of bits borrowed 88

Problem12:Problem12:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 55

Network Address:Network Address: 218.35.50.0218.35.50.0

For this problem the solutionFor this problem the solution

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.224255.255.255.224

Total number of subnetsTotal number of subnets 88

Number of usable subnetsNumber of usable subnets 66

Total number of host addressesTotal number of host addresses 3232

Number of usable addressesNumber of usable addresses 3030

Number of bits borrowedNumber of bits borrowed 33

Problem13:Problem13:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable hosts:Number of needed usable hosts: 2 52 5

Network Address:Network Address: 218.35.50.0218.35.50.0

For this problem the solution is:For this problem the solution is:

Information Information required required ValueValue

Address classAddress class CC

Default subnet maskDefault subnet mask 255.255.255.0255.255.255.0

Custom subnet maskCustom subnet mask 255.255.255.224255.255.255.224

Total number of subnetsTotal number of subnets 88

Number of usable subnetsNumber of usable subnets 66

Total number of host addressesTotal number of host addresses 3232

Number of usable addressesNumber of usable addresses 3030

Number of bits borrowedNumber of bits borrowed 33

Problem14:Problem14:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable subnets:Number of needed usable subnets: 1010

Network Address:Network Address: 172.59.0.0172.59.0.0

For this problem the solution is:For this problem the solution is:

Information Information required required ValueValue

Address classAddress class BB

Default subnet maskDefault subnet mask 255.255.0.0255.255.0.0

Custom subnet maskCustom subnet mask 255.255.240.0255.255.240.0

Total number of subnetsTotal number of subnets 1616

Number of usable subnetsNumber of usable subnets 1414

Total number of host addressesTotal number of host addresses 40964096

Number of usable addressesNumber of usable addresses 40944094

Number of bits borrowedNumber of bits borrowed 44

Problem15:Problem15:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable hosts:Number of needed usable hosts: 5050

Network Address:Network Address: 172.59.0.0172.59.0.0

For this problem the solution is:For this problem the solution is:

Information Information required required ValueValue

Address classAddress class BB

Default subnet maskDefault subnet mask 255.255.0.0255.255.0.0

Custom subnet maskCustom subnet mask 255.255.255.192255.255.255.192

Total number of subnetsTotal number of subnets 10241024

Number of usable subnetsNumber of usable subnets 10221022

Total number of host addressesTotal number of host addresses 6464

Number of usable addressesNumber of usable addresses 6262

Number of bits borrowedNumber of bits borrowed 1010

Problem16:Problem16:

In this problem, the following data is In this problem, the following data is given:given:

Number of needed usable hosts:Number of needed usable hosts: 2929

Network Address:Network Address: 23.0.0.023.0.0.0

For this problem the solution is:For this problem the solution is: