CCNA NOTE BOOK

Management in IP addressing

2011-02-14T08:45:00.001-08:00

Classful and Classless Addressing

VLSM

CIDR

Routing Table Structure

Routing Table lookup Process

Routing Behavior

Routing Table Labs

OBJECTIVES

By the end of this module, you should be able to understand:

What is the basic IP address and Subnet Mask of networking all about;

Fundamental idea of IP address and Subnet Mask

Understand the Classfull and Classless Concept.

Understand the Classes of IP address concepts

Understand the Variable Length Subnet Masks (VLSM) concept

Understand the Summarization concept

MIND MAP

IP address and Subnet Mask

In the topic you will learn more about how to find and understand the use of IP address and subnet mask. IP address as you know have two types

Classfull

Classless

Classfull is usually use and always interchange to Classless for example

Classfull : 200.100.10.1 with subnet 255.255.255.0 and can represent into

Classless: 200.100.10.1/24

Before you go deeper into subnetting you all need to know the Classfull IP address. From the table below you will easily identified the correct IP address and its subnet mask

Class	Valid dotted Decimal	Valid number	Subnet Mask ( Default )
A	A.X.X.X	1 – 126	255.0.0.0
B	B.B.X.X	128 – 191	255.255.0.0
C	C.C.C.X	192 - 233	255.255.255.0
Broadcast	255.255.255.255

Some valid subnet mask

Class	Subnet Mask	Bits value	CIDR value
A	255.0.0.0	11111111.00000000.00000000.00000000	/8
	255.128.0.0	11111111.10000000.00000000.00000000	/9
	255.192.0.0	11111111.11000000.00000000.00000000	/10
	255.224.0.0	11111111.11100000.00000000.00000000	/11
	255.240.0.0	11111111.11110000.00000000.00000000	/12
	255.248.0.0	11111111.11111000.00000000.00000000	/13
	255.252.0.0	11111111.11111100.00000000.00000000	/14
	255.254.0.0	11111111.11111110.00000000.00000000	/15
B	255.255.0.0	11111111.11111111.00000000.00000000	/16
	255.255.128.0	11111111.11111111.10000000.00000000	/17
	255.255.192.0	11111111.11111111.11000000.00000000	/18
	255.255.224.0	11111111.11111111.11100000.00000000	/19
	255.255.240.0	11111111.11111111.11110000.00000000	/20
	255.255.248.0	11111111.11111111.11111000.00000000	/21
	255.255.252.0	11111111.11111111.11111100.00000000	/22
	255.255.254.0	11111111.11111111.11111110.00000000	/23

Class	Subnet Mask	Bits Value	Note
C	255.255.255.0	11111111.11111111.11111111.00000000	/24
	255.255.255.128	11111111.11111111.11111111.10000000	/25
	255.255.255.192	11111111.11111111.11111111.11000000	/26
	255.255.255.224	11111111.11111111.11111111.11100000	/27
	255.255.255.240	11111111.11111111.11111111.11110000	/28
	255.255.255.248	11111111.11111111.11111111.11111000	/29
	255.255.255.252	11111111.11111111.11111111.11111100	/30
	255.255.255.254	11111111.11111111.11111111.11111110
	255.255.255.255	11111111.11111111.11111111.11111111	Broadcast

What you all must understand here is when you creating subnetting, always make sure that the bits 1's must be full from left to right. CIDR or classless inter domain routing is the number of 1's in IP address.

As you all know the host ID and Network ID is as followed:

Class	Format	Default Subnet Mask
A	network.host.host.host	255.0.0.0
B	network.network.host.host	255.255.0.0
C	network.network.network.host	255.255.255.0

For example:

Class	First Host	Network Address	Default Subnet Mask
A	10.0.0.1	10.0.0.0	255.0.0.0
B	176.17.0.1	176.17.0.0	255.255.0.0
C	192168..1	192.168.1.0	255.255.255.0

Example of Class A

Example of Class B

Example for Class C

Lets see focus on Class C IP address subnetting calculation. Let's find the subnet of network address for 190.160.1.0 using the subnet mask for

255.255.255.192 (/26)

255.255.255.224 (/27)

255.255.255.240 (/28)

255.255.255.240 (/29)

255.255.255.240 (/30)

Firstly you have to find following answer before to decide the subnetting for each subnet must.

How many subnets?

How many hosts per subnet?

What the valid subnets?

What the broadcast address for each subnet?

What are the valid hosts?

For 255.255.255.192 (/26)

How many subnets?

Since 192 is 2 bits on ( 11000000 ) , so the number of subnets would be 2²= 4

How many hosts per subnet?
- Since 192 is 6's bits off (11000000), so the number of host per subnets would be 2⁶ – 2 = 62 hosts

What the valid subnets?

256 – 192 = 64 , so our subnets are 0,64,128 and 192
- What the broadcast address for each subnet?

Because the next subnet is 64 so the broadcast address is 63

What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0,64,128,192

Subnet	0	64	128	192
First Host	1	65	129	193
Last Host	62	126	190	254
Broadcast	63	127	191	255

The possible network as below

For 255.255.255.192 (/27)

1. How many subnets?

Since 224 is 2 bits on ( 11100000 ) , so the number of subnets would be 2³= 8

2. How many hosts per subnet?

Since 224 is 5's bits off (11100000), so the number of host per subnets would be 2⁵ – 2 = 30 hosts

What the valid subnets?

256 – 224 = 32 , so our subnets are 0,32,64,96,128,160,192 and 224

4. What the broadcast address for each subnet?

Because the next subnet is 32 so the broadcast address is 31

5. What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0,32,64,96,128,160,192 and 224

Subnet	0	32	64	96	128	160	192	224
First Host	1	33	65	97	129	161	193	225
Last Host	30	62	94	126	150	190	222	254
Broadcast	31	63	95	127	159	191	223	255

For 255.255.255.192 (/28)

1. How many subnets?

Since 240 is 2 bits on ( 11110000 ) , so the number of subnets would be 2⁴= 16

2. How many hosts per subnet?

Since 240 is 4's bits off (11110000), so the number of host per subnets would be 2⁴ – 2 = 14 hosts

What the valid subnets?

256 – 240 = 16 , so our subnets are 0,16,32,48.64,80,96,112,128,144,160,176,192.208,224 and 240

4. What the broadcast address for each subnet?

Because the next subnet is 16 so the broadcast address is 15

5. What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0,16,32,48.64,80,96,112,128,144,160,176,192.208,224 and 240

Subnet	0	32	64	96	128	160	192	224
First Host	1	33	65	97	129	161	193	225
Last Host	30	62	94	126	150	190	222	254
Broadcast	31	63	95	127	159	191	223	255

For summary of class C, to make easy for you , you may remember this simple table of subnetting

Subnet Mask	Mask	Bit ON	Bit OFF	Block size	Subnet	Hosts
/25	128	1	7	128	2	126
/26	192	2	6	64	4	62
/27	224	3	5	32	8	30
/28	240	4	4	16	16	14
/29	248	5	3	8	32	6
/30	252	6	2	4	64	2

Subnetting Class B Addresses

Let's now focus on Class B IP address subnetting calculation. Let's find the subnet of network address for 170.160.0.0 using the subnet mask for

a. 255.255.128.0 (/17)

b. 255.255.192.0 (/18)

c. 255.255.240.0 (/20)

The method to find the subnetting for Class B is quite same as it is for Class C. But you must remember that you need start your finding in the third octet.

For . 255.255.128.0 (/17)

1. How many subnets?

Since 128 is 1 bits on ( 10000000 ) , so the number of subnets would be 2¹= 2

2. How many hosts per subnet?

Since 0 is 15's bits off (10000000.00000000), so the number of host per subnets would be 2¹⁵ – 2 = 32766 hosts

What the valid subnets?

256 – 128 = 128 , so our subnets are 0,128

4. What the broadcast address for each subnet?

Because the next subnet is 128.1 so the broadcast address is 127.255

5. What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0.0

Subnet	0.0	128.0
First Host	0.1	128.1
Last Host	127.254	255.254
Broadcast	127.255	255.255

For . 255.255.192.0 (/18)

1. How many subnets?

Since 192 is 2 bits on ( 11000000 ) , so the number of subnets would be 2²= 4

2. How many hosts per subnet?

Since 0 is 14's bits off (11000000.00000000), so the number of host per subnets would be 2¹⁴ – 2 = 16382 hosts

What the valid subnets?

256 – 192 = 164 , so our subnets are 0,64,128,192

4. What the broadcast address for each subnet?

Because the next subnet is 64.1 so the broadcast address is 63.255

5. What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0.0 to 192.255

Subnet	0.0	64.0	128.0	192.0
First Host	0.1	64.1	128.1	192,1
Last Host	63.254	127.254	191.254	255.254
Broadcast	63.255	127.255	191.255	255.255

For . 255.255.240.0 (/20)

1. How many subnets?

Since 249 is 4 bits on ( 11110000 ) , so the number of subnets would be 2⁴= 16

2. How many hosts per subnet?

Since 0 is 12's bits off (11110000.00000000), so the number of host per subnets would be 2¹² – 2 = 4094 hosts

What the valid subnets?

256 – 240 = 16 , so our subnets are 0,16,32,48,64,80,96,112,128,144,160,176,192,208,224,240

4. What the broadcast address for each subnet?

Because the next subnet is 240.1 so the broadcast address is .255

5. What are the valid hosts?

This valid hosts can be find by selecting the IP address between subnet and broadcast of 0.0

First nine of the subnet

Subnet	0.0	16.0	32.0	48.0	64.0	80.0	96.0	112.0	128.0
First Host	0.1	16.1	32.1	48.1	64.1	80.1	96.1	112.1	128.1
Last Host	15.254	31.254	47.254	63.254	79.254	95.254	111.254	127.254	143.254
Broadcast	15.255	31.255	47.255	63.255	79.255	95.255	111.255	127.255	143.255

Subnetting Class A Address

Now lets us see the Class A subnetting and the Class A as followed

255.0.0.0 (/8)

255.128.0.0 (/9)

255.1920 (/10)

255.224.0 (/11)

255.240.0 (/12)

255.248.0.0 (/13)

255.252.0.0 (/14)

255.254.0.0 (/15)

255.255.0.0 (/16)

For example , lets us discuss one of the subnet (/8) or 255.0.0.0 or

11111111.00000000.00000000.00000000.

1. How many subnets?

Since 255 is 8 bits on ( 11111111 ) , so the number of subnets would be 2⁸= 256

2. How many hosts per subnet?

Since 0 is 16's bits off (00000000.00000000.00000000), so the number of host per subnets would be 2¹⁶ – 2 = 65534 hosts

What the valid subnets?

256 – 255 = 1 , so our subnets are 0,1,2,3,4,5 up to 256 subnets. The subnet would be 10.0.0.0, 10.1.0.0 up to 10.255.0.0

4. What the broadcast address for each subnet?

Because the next subnet is 10.1.0.0 so the broadcast address is 10.0.255.255

5. What are the valid hosts?

These valid hosts can be find by selecting the IP address between subnet and broadcast.

Subnet	10.0.0.0	10.1.0.0	…….	10.254.0.0	10.255.0.0
First Host	10.0.0.1	10.1.0.1	…….	10.254.0.1	10.255.0.1
Last Host	10.0.255.254	10.1.255.254	…….	10.254.255.254	10.255.255.254
Broadcast	10.0.255.255	10.1.255.255	…….	10.254.255.255	10.255.255.255

Variable Length Subnet Masks (VLSM)

As you working more with subnet problems, you will come across with a network too big or large and not practical to be use or implement subnetting. So, VLSM concept is creating subnet in a subnet itself. By applying these VLSM methods the network become more convenient and more practical as the need of a certain network. VLSM also help you to utilize and design a better network without wasting the IP addresses usage.

As we mention above, VLSM is another important and useful network configuration that need to be discuss by example.

Example 1:

You need to design a network with different location and host, lets say

Kuala Lumpur : 55 host

Putra Jaya : 25 host

Serdang : 12 host

STEP 1.

Firstly you need calculate the biggest number of hosts and followed with the smaller number of hosts.

For Kuala Lumpur, we need 55 host

So , 2^x – 2 = 55 hosts ,

2^x- 2 => 55 , from this we can fin the of X , X represent the number of bits

2⁶– 2 => 55 , the value of 6 is selected because the nearest number to number 55.

So, 2⁶– 2 => 55 host and the host bit is 6. As 6 host bit will the host addresses and the other 2 bit will be the network addresses.

How many subnets?

Since 192 is 2 bits on ( 11000000 ) , so the number of subnets would be 2²= 4.

What the valid subnets?

So, the valid subnet is 256 – 192 = 64 , so our subnets are 0,64,128 and 192

Now you can aspect you will have 4 subnet starting with 0, 64, 128 and 192. So VLSM will help you to reduce wasting IP addresses. We will start to create valid subnet under this 4 main subnet.

For, Kuala Lumpur with 55 hosts, you have known that the host bit is 6, there for you will adding 2 bit as the network bit , therefore now the network address will become :

192.168.10.0/24 to 192.168.10.0/26

Subnet Mask	Bit Network	Number of Host	Host required
255.255.255.192	/26	62	55
255.255.255.128	/25	126
255.255.255.0	/24	254
Octet 1	. Octet 2	.Octet 3	.Octet 4
11111111	.11111111	.11111111	.00000000	/24
11111111	.11111111	.11111111	.11000000	/26

You can see an additional 2 bit added to Octet 4

	Valid Subnet	Number of Subnet	Network ID	Broadcast
192.160.10.0/24	192.160.10.0/26	0	192.160.10.0/26	192.160.10.63/26
	192.160.10.64/26	1	192.160.10.64/26	192.160.10.127/26
	192.160.10.128/26	2	192.160.10.128/26	192.160.10.191/26
	192.160.10.192/26	3	192.160.10.192/26	192.160.10.255/26

From this you can used the subnet number 55 for Kuala Lumpur.

Valid Subnet

Valid Range

Subnet Mask

Network ID

Broadcast

192.160.10.0/26

192.168.10.1 – 192.160.10.62

255.255.255.192

192.160.10.0/26

192.160.10.63/26

For Putra Jaya with 25 hosts,

So , 2^x – 2 = 25 hosts ,

2^x- 2 = 25 , from this we can fin the of X , X represent the number of bits

2⁵– 2 => 25 , the value of 5 is selected because the nearest number to number 25.

So, 2⁵– 2 = 32 host and the host bit is 5. As 5 host bit will the host addresses and the other 3 bit will be the network addresses.

How many subnets?

Since 224 is 3 bits on ( 11100000 ) , so the number of sub-subnets would be 2¹= 2.

What the valid subnets?

So, the valid subnet is 256 – 224 = 32 , so our subnets are 0,32,64,96,128,160, and 192

Subnet Mask	Bit Network	Number of Host	Host required
255.255.255.224	/27	32	25
255.255.255.192	/26	62	55
255.255.255.128	/25	126
255.255.255.0	/24	254
Octet 1	. Octet 2	.Octet 3	.Octet 4
11111111	.11111111	.11111111	.00000000	/24
11111111	.11111111	.11111111	.11000000	/26
11111111	.11111111	.11111111	.11100000	/27

You can see an additional 1 bit added to Octet 4, and new subnet is 192.168.10.0/26 to 192.168.10.0/27, subnet mask is 255.255.255.224. When you added a bit and now number of sub-subnet possible is 2¹= 2. You can see each /26 can assign 2 subnet or sub-subnet.

Valid Subnet	Sub-subnet	Number of Subnet	Network ID	Broadcast
192.160.10.64/26	192.160.10.64/27	1	192.160.10.64/27	192.160.10.95/27
192.160.10.64/26	192.160.10.96/27	0	192.160.10.96/27	192.160.10.127/27
192.160.10.128/26	192.160.10.128/27	1	192.160.10.128/27	192.160.10.159/27
192.160.10.128/26	192.160.10.160/27	0	192.160.10.160/27	192.160.10.191/27
192.160.10.192/26	192.160.10.192/27	1	192.160.10.192/27	192.160.10.223/27
192.160.10.192/26	192.160.10.244/27	0	192.160.10.224/27	192.160.10.255/27

Finally the number of network addresses for Putra Jaya can be summarized as:

Valid Subnet

Valid Range

Subnet Mask

Network ID

Broadcast

192.160.10.64/27

192.168.10.65 – 192.160.10.95

255.255.255.224

192.160.10.64/27

192.160.10.95/27

For Serdang with 12 host

So , 2^x – 2 = >12 hosts ,

2^x- 2 => 12 , from this we can fin the of X , X represent the number of bits

2⁴– 2 =>12, the value of 4 is selected because the nearest number to number 12.

So, 2⁴– 2 = 14 host and the host bit is 4. As 4 hosts bit will be additional to host addresses and the other 4 bit will be added to network addresses.

How many subnets?

Since 240 is 4 bits on (11110000) , so the number of sub-subnets (add one bit to subnet) would be 2¹= 2.

What the valid subnets?

So, the valid subnet is 256 – 240 = 16, so our subnets are 0,16,32,48,64,80, and 192

Subnet Mask	Bit Network	Number of Host	Host required
255.255.255.240	/28	14	12
255.255.255.224	/27	30	25
255.255.255.192	/26	62	55
255.255.255.128	/25	126
255.255.255.0	/24	254
Octet 1	. Octet 2	.Octet 3	.Octet 4
11111111	.11111111	.11111111	.00000000	/24
11111111	.11111111	.11111111	.11000000	/26
11111111	.11111111	.11111111	.11100000	/27

Valid Subnet	Sub-subnet	Number of Subnet	Network ID	Broadcast
192.160.10.64/26	192.160.10.64/27	1	192.160.10.64/27	192.160.10.95/27
192.160.10.64/26	192.160.10.96/27	0	192.160.10.96/27	192.160.10.127/27
192.160.10.128/26	192.160.10.128/27	1	192.160.10.128/27	192.160.10.159/27
192.160.10.128/26	192.160.10.160/27	0	192.160.10.160/27	192.160.10.191/27
192.160.10.192/26	192.160.10.192/27	1	192.160.10.192/27	192.160.10.223/27
192.160.10.192/26	192.160.10.244/27	0	192.160.10.224/27	192.160.10.255/27

Finally the number of network addresses for Serdang can be summarized as

Valid Subnet

Valid Range

Subnet Mask

Network ID

Broadcast

192.160.10.96/27

192.168.10.113 – 192.160.10.126

255.255.255.224

192.160.10.112/27

192.160.10.127/27

We selected this range of subnet because we need only 12 host so we can used the unused subnet at /27

Summary :

The valid IP address 192.168.10.0/26 is used for Kuala Lumpur

By using VLSM methods we optimize one of the subnet 192.168.10.64/26 to sub-subnet of 192.168.10.64/27 and 192.168.10.96/27.

The valid IP address 192.168.10.64/27 is used for Putra Jaya.

The valid IP address 192.168.10.96/27 is used for Serdang.

Classless interdomian routing (CIDR)

Classless interdomian routing is a method to customize or modified way to use prefix based standard in analyzing an IP address. This CIDR technique makes capable to simplest a complex and multiple networks, a mass of addresses into a single route. CIDR will provide us the information to the IP address is noted as four octets and subnet mask. For example:

178.163.10.0/24

192.163.10.0/24

202.163.10.0/24

222.163.10.0/24

Route Summarization

What you are going to learn from this topic is to route summarize or aggregation of many networks addresses to one or single address with shorter subnet mask. The purpose of this technique is to reduce space the size of the routing table. As we that noted CIDR also a same method of router summarization and supernetting.

There some difference about CIDR, CIDR do not take into account the restriction of classful limitations and permits any summarization with masks lesser compare to the default classful mask.

This route summarization helps the route to reduce the resource and bandwidths utilization for routing updates. As the consequent the time to updating the routing table becomes faster and more efficient.

Noted that the only routing protocol applied this supernetting is the classless IP addressing. Because of classless routing protocol utilities the network address and mask when updating routing

By using the summarization technique Router A will allowed all IP with /24 to be forward to Router B. How to use this summarization technique you need to find out the block size.

Calculation Route Summarization

How about when you have only 4 IP address! For example, what the best IP address summarization for Router B ?

The most important find out the block first. So you can summarize 192.160.0.0/20 using a mask of 255.255.240.0, so block size is 256-240 = 16.

	Octet1	.Octet2	.Octet3	.Octet4	Mask
192.160.4.0/24	11000000	.10100000	.00000100	.00000000	255.255.252.0
192.160.5.0/24	11000000	.10100000	.00000101	.00000000	255.255.253.0
192.160.6.0/24	11000000	.10100000	.00000110	.00000000	255.255.254.0
192.160.7.128/25	11000000	.10100000	.00000111	.10000000	255.255.255.128
192.160.8.192/26	11000000	.10100000	.00001000	.11000000	255.255.255.192
192.160.0.0/20	11000000	.10100000	.00000000	.00000000	255.255.240.0

Another example:

There few step to be followed to makes the summarization, Step 1 list the networks in binary arrangement. Step 2, find the leftmost matching to decide the mask or /14 or 255.252.0.0

		Octet1	.Octet2	.Octet3	.Octet4	Mask
S T E P 1	192.20.0.0/16	11000000	.00010100	.00000000	.00000000	255.255.252.0
	192.21.0.0/16	11000000	.00010101	.00000000	.00000000	255.255.253.0
	192.22.0.0/16	11000000	.00010110	.00000000	.00000000	255.255.254.0
	192.23.0.0/16	11000000	.00010111	.00000000	.00000000	255.255.255.128
S T E P 2			Select the same bits in this case bit 6's are same
S T E P 2	192.20.0.0/14	11000000	.00010100	.00000000	.00000000	255.252.0.0

For the result, we can show the summarization of 192.20.0.0/14 as

192

Copy the leftmost matching bit up to 14 bits

Add zero bits

Routing Table Structure

The understanding of router table structure is to ensure that we know what is happening when we punch the key board. In this session we will learn how the router works will each IP address and interfaces. Three major things will cover are the Level 1 Router, Level 2 router and Next Hop IP address or Exit interface. As we known that Cisco router is design in hierarchical methods, the purpose of this is to makes the router works faster and accurately.

Let we looks a simple topology for easy and better understanding about routing table structure.

Router	Ethernet	Serial 1	Serial 0
R1	E0 (192.162.1.1)		S0 ( 192.162.2.1)
R2	E0(192.162.3.1)	S1 (172.162.1.1)	S0 ( 192.162.2.2)
R3	E0 (192.162.4.2)	S1(172.162.1.2)

Form the topology , we can see the connection between router 1,2 and 3 where the interface that involved can be see clearly: the serial 0 and 1 and Ethernet. By provide the diagram we can easily the configuration but it applied for simple networks only. Basically this diagram is suitable for starting point for new learner. Simply we can describe the network easily and clearly with any confusing.

The Router R1 and R2 share same network ( 192.162.0.0/16) with 24 subnet. For Route R2 and R3 linked by 172.162.1.0/24. Router R3 in addition has 192.162.4.0/24 and known as disconnected or discontiguous network of 192.162.0.0. From the diagram we can also clearly the connection of serial and Ethernet with their IP address. E.g. R1 : EO – 192.162.1.1, S0 – 192.162.2.1 ; R2 : S0 – 192.162.2.2, S1 – 172.162.1.1, E0 – 192.162.3.1 ; R3 : S1 – 172.162.1.2 , E0 – 192.162.4.2. Hoping by using this table we will not makes any mistake we configuration the router.

Routing Table lookup Process

Routing Behavior

Summary

The two type of IP address are :
- Classfull
- Classless

Classfull is usually use and always interchange to Classless

Class A IP addresses with valid dotted decimal : A.X.X.X

Class B IP addresses with valid dotted decimal : B.B.X.X

Class C IP addresses with valid dotted decimal : C.C.C.X

IP address divided into network address (A,B,C) and host address ( X ) .

TEST ONE

The maximum IP address for 255.255.255.240?
1. 14
2. 15
3. 16
4. 30

The maximum subnet for 255.255.255.240?
1. 14
2. 15
3. 16
4. 30

If you have 16 subnets, how many bits must you borrow from the host field?
1. 2
2. 3
3. 4
4. 5

The mask for /28 for Class C is?
1. 255.255.255.255
2. 255.255.255.254
3. 255.255.255.240
4. 255.255.255.224

A network address of 172.17.0.0/18 provides how may subnets and hosts?
1. 2 subnets and 30 hosts
2. 2 subnets and 32 hosts
3. 4 subnets and 30 hosts
4. 4 subnets and 32 hosts

The IP address 172.17.45.5/30 belongs to?
1. 172.17.40.0
2. 172.17.40.4
3. 172.17.40.8
4. 172.17.40.12

The subnetwork for IP address 172.16.50.0/21 is?
1. 172.17.36.0
2. 172.17.48.0
3. 172.17.64.0
4. 172.17.72.0

How many host can you aspect with the IP address of 192.168.100.10/28?
1. 4
2. 8
3. 16
4. 32

What the block size of the subnet 192.168.10.10/29?
1. 8
2. 16
3. 32
4. 64

What is the broadcast IP address that available with in subnet 192.168.10.10/29?
1. 192.168.10.0 255.255.255.255
2. 192.168.10.15 255.255.255.248
3. 192.168.10.27 255.255.255.248
4. 192.168.10.31 255.255.255.240

What is the broadcast IP address that available with in subnet 192.168.10.10/28?
1. 192.168.10.15 255.255.255.240
2. 192.168.10.15 255.255.255.248
3. 192.168.10.27 255.255.255.248
4. 192.168.10.31 255.255.255.240

Find the valid subnet for 172.110.122.1/25?
1. 172.110.122.0
2. 172.110.16.0
3. 172.110.32.0
4. 172.110.64.0

What is the valid host address for 172.17.16.0/22.?
1. 172.17.18.255 255.255.252.0
2. 172.17.17.0 255.255.255.255
3. 172.17.100.0 255.255.240.0
4. 172.17.200.0 255.255.255.0

2011-01-13T09:04:00.001-08:00

Introduction to Routing and Packet Switching Networks

Inside the Router
CLI Configuration and Addressing
Building the Routing table
Path Determination and switching Functions

Objective

Identify a router as a computer with an OS and hardware designed for the routing process.
Demonstrate the ability to configure devices and apply addresses.
Describe the structure of a routing table.
Describe how a router determines a path and switches packets

Introduction

Router as a computer

The basic purpose of a router is to route in and out from the source of information to its destination with specific addresses. Route works as computers that focus and specific in sending packets of data over the data network across the globe. Route have a special task and responsible for the purpose of interconnecting among networks by choosing the best path or route for a packet data to travel and forwarding packet data to their destination. Router is just like a postmaster of the network, where all needed information is available to the journey of the packet data from its source to its destination.

Routers works as the network center where all related information must pass through a specific route to ensure all packets data will be forwarded for its source to its destination correctly. In general routers have 2 obvious connections:

WAN connection (involve public ISP)
LAN connection

The main purpose of this router in the network is to ensure and examine the entire data packet's passes through its and verify all of the data packets destination IP address, and finally determines the finest path by obtain the assist of a routing table. This mean that the final route will be determines by the most reliable route of the routing table.

Inside the Router

The inside of a router is most likely least that mother board of a computer system. It consists of CPU, ROM, RAM, NVRAM, Flash memory and Interfaces. The design of a router maybe different from one manufacturing to other manufacturing company but the basic component is almost the same.

Inside the Router

In most routers the interface types and function are almost the same:

Ethernet / fast Ethernet interfaces

Serial interfaces
Management interfaces

This interfaces have different function due to different application of devices connected the router.

Router Bootup Process

The bootup of a router is just similar to a computer. Systemic process is used by the router when its bootup. What happen here is just like a computer will sequence bootup form one devices to other devices. This including testing the software , hardware, operating system.

Bootup Process

The major phases to the router boot-up process are router will test and check the router hardware. The router will test router hardware. The bootup process usually started with Power-On Self Test (POST), Loading the Bootstrap program &

Executing bootstrap loader, Locate & load Cisco IOS software –Locate the IOS & cconfiguration File and Loading the IOS and finally locating & loading startup configuration file or enter setup mode. At this point the bootstrap program appears for the configuration file. In some cases when the startup configuration file can not be found, the router automatically wills the user to enter setup mode. This setup mode will provided the most basic configuration information about the router.

Main Step of the Bootup Process for a router (Cisco router) :

POST ( Power On Self Test)

Loading the Bootstrap program

Locating Cisco IOS

Loading Cisco IOS

Locating the Configuration File

Loading the Startup Configuration File or Entering Setup Mode

After all processes involve with the bootup is ready , router will proceed to the next level of process for validating the router boot-up process:

The show version command is used to view information about the router during the bootup process. Information includes:

Building the Routing Table

The main purpose of a router is to forward the data packet to its destination according to the destination IP address. This process can be done if the router has all the required information stored in its routing table. Routing table will provided the best information of the path available to the data packets destination.

Routing table

Routing table is a random access memory (RAM) that capable to accumulate important information related to the best path destination of the data packets. This information is useful for the router before forwarding the data packet, this include the directly connected and remote or adjacent network, next hop that represent another router in the network.

Router A is directly connected to Router B and Router C is remotely connected. In this case Router C can be the net hop outgoing or exit interface of Router A before reach the final destination.

Always, remember that when dealing with the router is careful of the router interfaces. This is because wrong configuration on the interface will cause your nightmare on troubleshooting a faulty network.

There three important in understanding the connection of a route:

Directly connected routes – All neighbour or nearest or next door routers connection is directly connected to the route interface.

Static Router – A single path for the router to send or received the packets data among routers.
Dynamic router – The option that being provide by the router to choose any new path at any point in order to reach its destination.

The routing table of a router can be display with # show ip route command.

We can see that there is no static and dynamic routing protocol is used. Only the directed connected protocol is used.

C: represent a directly connected route
198.198.1.0, show the network address of the directly connected route
Ethernet 0 and Serial 0 are the interface being used to reach this network.

Directly Connected Network

The concept of host, network and subnet mask is important in designing a network. As we know computer or network devices usually only has a single interface e.g. NIC compare to router. Router was purposely design to have multiple interface, the most simple router have two interface the serial , S0 and Ethernet , E0. In dealing with configuration of a network, the ideal of network address and host address is important. Also remember that host is subset of network in IP addressing.

From this diagram, if we configure PC 1 to 198.198.1.2 and subnet 255.255.255.0, now PC1 become a member of 198.198.1.0/24 network. This also happens to Ethernet interface, E0, e.g. we configure with 198.198.1.1. But for serial interface, S0, the interface is member of the next network, 198.198.2.0. The network 198.198.1.0 and 198.198.2.0 is different network. To active the configured data of the network the command no shut is applied.

Static and dynamic route usually be configure after the existing of directly connected route. The directly connected have to be configure first and it just to be come mandatory to have directly connected route in a router before any routing can be done.

Static Routing

The main function of static routing and dynamic routing protocol are to enable remote network in to the routing table of existing router. Static router consist of network address and subnet mask of the remote network.

Static routing usually applied to a network with few routers, connection to internet with single ISP and a large network with hub and spoke topology.

Dynamic Routing

Same as static routing , dynamic routing also can de added in the routing table. The earliest dynamic routing is the routing information protocol (RIP).

Dynamic routing protocols provide important information regarding the network. The most typical information activities are network discovery and updating and maintaining routing tables' information. Dynamic routing protocol share information of known network among routers that using the same routing protocol. Dynamic routing protocol also can learn any networks that are connected via other routers. Some of dynamic routing protocol are RIP, IGRP, EIGRP, OSPF, IS-IS and BGP.

Routing Table Principle

Path Determination and Switching Functions

In this section we wile learn how that data packet is travelling from one hop to another hop until it reach it destination. This will include how the frame field change in their journey.

The Routing Table

2011-01-13T08:46:00.000-08:00

Buiding Routing Table

The main purpoe of a router is to forward the data packet to its destination according to the destination IP address. The process can be done if the router has all the required information stored in its routing table. Routing table will provided the best information of the path available to the data packets destination.

Router as a computer

2009-08-09T23:06:00.000-07:00

Router as a computer

The basic purpose of a router is to route in and out from the source of information to its destination with specific addresses. Route works as computers that focus and specific in sending packets of data over the data network across the globe. Route have a special task and responsible for the purpose of interconnecting among networks by choosing the best path or route for a packet data to travel and forwarding packet data to their destination. Router is just like a postmaster of the network, where all needed information is available to the journey of the packet data from its source to its destination.

Routers works as the network center where all related information must pass through a specific route to ensure all packets data will be forwarded for its source to its destination correctly. In general routers have 2 obvious connections:

• WAN connection (involve public ISP)
• LAN connection

The main purpose of this router in the network is to ensure and examine the entire data packet’s passes through its and verify all of the data packets destination IP address, and finally determines the finest path by obtain the assist of a routing table. This mean that the final route will be determines by the most reliable route of the routing table.

Inside the router

Component Function
1 CPU Executes operating system instructions
2 Read-only memory (ROM) Holds diagnostic software used when router is powered up. Stores the router’s bootstrap program.
3 Non-volatile RAM (NVRAM) Stores startup configuration. This may include IP addresses (Routing protocol, Hostname of router)

4 Flash memory Contains the operating system (Cisco IOS)

5 Interfaces There exist multiple physical interfaces that are used to connect network.
6 Random access memory (RAM) Contains the running copy of configuration file. Stores routing table. RAM contents lost when power is off

Summary

 Routers are computers that specialize in sending data over a network.
 Routers are composed of:
-Hardware i.e. CPU, Memory, System bus, Interfaces
-Software used to direct the routing process
 IOS
 Configuration file
 Routers need to be configured. Basic configuration consists of:
-Router name
-Router banner
-Password(s)
-Interface configurations i.e. IP address and subnet mask
 Routing tables contain the following information
-Directly connected networks
-Remotely connected networks
-Network addresses and subnet masks
-IP address of next hop address

 Routers determine a packets path to its destination by doing the following
 Receiving an encapsulated frame & examining destination MAC address.
 If the MAC address matches then Frame is de-encapsulated so that router can examine the destination IP address.
 If destination IP address is in routing table or there is a static route then Router determines next hop IP address. Router will re-encapsulate packet with appropriate layer 2 frame and send it out to next destination.
 Process continues until packet reaches destination.
 Note - only the MAC addresses will change the source and destination IP addresses do not change.

Source : CISCO , CCNA2 Router and Routing Basic

Connection-Oriented Protocols:

2009-06-30T23:46:00.000-07:00

Connection-Oriented Protocols:

The principally important characteristic of a connection oriented protocols is to facilitate a logical connection exist and recognized among two devices ahead of transferring a stream of data. Connection-oriented protocol might be present apply in the data link layers of the protocol stack or in the transport layers of the protocol stack, depending lying on the physical connections within place and the services essential via the system so as to be communicating.

Normally the achievements by subsequent a particular set of regulations that point out how a connection must be begin, talk, administer and terminated. Frequently it started with one host or device commences by sending a request to start a connection, and the other host or devices willpower respond. These hosts or devices resolve set the standard control information towards consent lying on and how the connection should be set up. If this is satisfying and victorious, data is sent between the hosts or devices. When it is done, the link willpower terminated.

Example of a connection-oriented protocol at the transport layer is the TCP protocol.

The communication sitting can be a circuit switched connection, or a virtual circuit connection within a packet switched network. For example the transport layer is the TCP protocol.

Simplex, Half-Duplex and Full Duplex Operation

2009-06-23T21:10:00.000-07:00

Simplex, Half-Duplex and Full Duplex Operation

Simplex – The signal be sent away in unidirectional mode. This indicate the signal is sent away form the resource to the destination merely. The signal movements in single direction only. E.g. television or radio transmission.

Half-Duplex - Contrast to simplex communication, half duplex message authorized the traffic to travel in mutually directions. Half duplex merely approved the signal to pass through both direction but at the same time. This way that the signal have to be sent out first and finish the session as of a place and then simply the reception signal be able to be sent in and the session end from a station. Half duplex only authorized an only signal stream in one method or direction at an instant.

Full-Duplex transmission – It be able to function or effort in two-way course at a similar time. For the reason that of this, proficient full duplex enlarge the act of the networks. It can be sent and receive at the same without any problem. Full Duplex make use of two couple of wires where permit the station to transmit and obtain signal at any occasion. Full Duplex authorized he signal stream in mutually direction at the same time.

2009-06-23T20:57:00.000-07:00

MAC addressing

MAC addressing short form of Media Access Control address. MAC provide the physical or devices or hardware address. MAC provide adrress on the network interface card (NIC), which located int the Layer 2 addresses. MAC address is very unique . The usual MAC addressing format is

XX:XX:XX:YY:YY:YY

Note ; XX:XX:XX = ID number of the adapter manufacture and

YY:YY:YY = serial number of manufacture. MAC address usually used the hexadecimal numbering format.

Network Interface Cards and Modem

2009-05-13T21:05:00.000-07:00

The most important devices in networking , with them there will be not networking world

• NIC - Is a printed circuit board (PBC) that allows communication to and from a computer to the out side world. NIC requires Interrupt Request (IRQ), Input/Output (I/O), memory space and driver to perform it functions. Today NIC is simply installed to the computer. The plug and play concept is used to installed NIC driver. You only need to slot the NIC to the computer expansion slot and run the driver software and wait for successful result of the installation.

• Modem - A device that enable the computer to communicate to the world via telephony line. At this point, the modem will connect your computer to the outside virtually via Public Switched Telephone Network (PSTN). The function of a modem is to convert digital signal to an analog signal before entering the PSTN, then convert the analog signal to digital signal when the signal reaches its destination. Converting from digital to analog is known as modulation and analog to digital signal is known as demodulation. There are two types of modem communication: the first type known as asynchronous and the second type is known as the synchronous. Asynchronous communication means that the entire signal will be sent including specified character with control bits which consists of start bits and stop bits. These bits will differentiate between the starting bits and the ending bits. Synchronous communication means that the data will be sent out in blocks of bytes. This blocks of bytes is analyzed, verified and acknowledged by the computer on the destination side and it is asked to accept or reject the blocks. If rejected, the blocks are requested to be resent.

Remember this:

Network Interface Cards
1. Design within PCB
2. Usually use the plug and play methods
3. needs Interrupt Request (IRQ), Input/Output (I/O), memory space and a driver

Modems
1. Connect the outside virtually via Public Switched Telephone Network (PSTN).
2. convert digital signal to an analog signal before entering the PSTN
3. convert the analog signal to digital signal when the signal reaches its destination.
4. two types of modem : asynchronous modem and synchronous modem.

Networking and Internet connectivity

2009-03-07T11:00:00.000-08:00

Introduction to Networking

What is networking? For sure you guys out there known about network! If not much but still you guys out there have some basic idea of networking.

This chapter will provide you general information’s what all is about of networking. Networking is something very wide. Starting with a computer, and makes it’s connecting to another computer throughout the world. From a simple network, it’s later become very huge computer networking know as the internet.

The Fundamentals of Internet Connectivity

What we can say about internet? Internet is like a multimillions of computers that are connected and gather together sharing information at the speed of light, perhaps. This means that internet was buildup via multimillions of computers in the globe. The internet nowadays are known as data networking, computer networking or others terms. But still internet started with a computer and connected to each other to become super computer connecting or networking.

The connection of the internet must start with physical connection, than logical connecting and finally the software applications. The physical connection are done from the PC to the network by network interface card (NIC) or modem, with special cable. The logical connection is a standard protocol to ensure the data flow that as required and planed. Some of this logical connection such as Transmission Control Protocol / Internet Protocol ( TCP/IP )
You will learn more detail about the TCP/IP chapter. Finally, the application will be interpreted as data and displayed as receiving information or data which in the form understandable manner.

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Application Layer

2009-01-05T19:31:00.000-08:00

Application Layer

The application layer is the most upper layer in the TCP/IP model. This Application layer is use to operate high level protocols and problem of representations, encoding and dialog control. Application layer involving several applications such as file transfer, e-mail, remote login, network management, name management and used by the router. Some of applications that supported by TCP/IP were HTTP, TFTP, FTP, NFS, SMTP, Telnet, SNMP and DNS.

All application layer will functional to make sure the all data that applied at this layer will properly packaged for next layer function. In this application layer there other application program that is very useful in the networking. Some of the were netBIOS application, Windows sockets, Sockets and NetBIOS over TCP/IP.

http://ccna--note-book.blogspot.com/rss.xml and http://ccna-note-book.blogspot.com/

CCNA,CCNP,CCIE, TCP / IP , HTTP, TFTP , NFS, SMTP, Telnet, SNMP and DNS

TCP/IP Configuration

2008-12-16T09:57:00.000-08:00

TCP/IP Configuration

Every one of you must know what TCP/IP what all is about. But in this blog I will only brief out what is TCP/IP.

TCP/IP was firstly introduced by US Department of Defense in their project known as Advance Research Project Agency. TCP/IP is a set of protocol that is required to allowed computer to communicate and share information among computer and the network. TCP/IP protocol today is available in PCs, UNIX workstations, minicomputers, Macintosh computers and mainframes. With this TCP/IP has enabled the connectivity among the multimillions of computers, commercial network and the internet.

Basically, TCP/IP operation required the pc IP address, subnet mask, default gateway, domain name server (DNS) information and Dynamic Host Configuration Protocol (DHCP) in order to be functioning. You will need to use PING command to test it functional. You need to ping you local back address, IP address of host computer, default gate-way and remote destination IP address Be patient, you learn more about the configuration, may be for rest of your live, if you that network expert as you career.

Anywhere thanks alot to GOOGLE.COM for the greate search engine!!!!

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