Example 8: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP: 172.16.225.10/18

Find Network ID?

Calculating Network Portion

Converting IP Address to Binary

                                                                   225 – 11100001

IP and Subnet Mask in Binary

Network ID Rule ->           Network – Constant

                                           Host       - Zero’s

Make Host as 0's

So Network ID 172.16.192.0

Example 7: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP                           : 10.255.50.7/17

Find the Network ID?

Answer:

/17 Means 17 Bits are Network Bits

Without Writing Mask, we are mentioning like this

Converting IP Address to Binary

                                                               50 – 00110010

IP and Subnet Mask in Binary

Network ID Rule ->           Network – Constant

                                           Host       - Zero’s

Make Host as 0's

Network ID is 10.255.0.0

Example 6: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP                           : 172.16.1.126

Subnet Mask         : 255.255.255.128

Find the Network ID?

Answer:

Converting IP Address to Binary

Converting IP Address to Binary

                                           

126 – 11111110                                                    128 – 01000000

IP and Subnet Mask in Binary

Network ID Rule ->           Network – Constant

                                           Host       - Zero’s

Make Host as 0's

So Network ID is 172.16.1.0

Example 5: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP                           : 172.16.5.225

Subnet Mask         : 255.255.255.192

Find the Network ID?

Answer:

Converting IP Address to Binary

                                           
  Converting IP Address to Binary

For IP 192, Binary is  11000000 

For IP 225, Binaryl is  11100001

IP and Subnet Mask in Binary

24 + 2 (2 Bits Borrowed) = 26 Bits Network Portion 

Network ID Rule ->           Network – Constant

                                           Host       - Zero’s

Make Host as 0's

So Network ID is 172.16.5.192

Example 4: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP - 192.168.1.0 / 24

Need 3 Subnet with Each 50 Hosts?

Answer:

Result Imagination Diagram

Already Class C Given.So we will Calculate host using class C

Calculating Host's

So 6 bit's is enough to get 50 hosts

Sub-netting

1^st Subnet: (Vlan 1)

1st Subnet

Network ID            : 192.168.1.64

1^st Host ID             : 192,168.1.65

Last Host ID            : 192.168.1.126

Broadcast ID           : 192.168.1.127

Subnet Mask               : 255.255.255.192

2^nd Subnet (Vlan 2)

2nd Subnet

Network ID            : 192.168.1.128

1^st Host ID             : 192.168.1.129

Last Host ID          : 192.168.1.190

Broadcast ID         : 192.168.1.191

Subnet Mask             : 255.255.255.192

3^rd Subnet (Vlan 3)

3^rd Subnet

Network ID            : 192.168.1.192

1^st Host ID             : 192.168.1.193

Last Host ID          : 192.168.1.254

Broadcast ID         : 192.168.1.255

Subnet Mask             : 255.255.255.192

Example 3: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

Example 3

Answer:

v  We Need 3000 Host

v  Class – B is enough to get 3000 Host (We can Choose Class-A Also)

Calculating Host's

So 10 Bit is Enough to get 1000 Host

Sub-netting

1^st Subnet: (Vlan X)

1st Subnet

Network ID            : 172.16.4.0

1^st Host ID             : 172.16.4.1

Last Host ID              : 172.16.7.254

Broadcast ID             : 172.16.7.255

Subnet Mask               : 255.255.252.0

2^nd Subnet: (Vlan Y)

2nd Subnet

Network ID            : 172.16.8.0

1^st Host ID             : 172.16.8.1

Last Host ID                : 172.16.11.254

Broadcast ID               : 172.16.11.255

Subnet Mask               : 255.255.252.0

3rd Subnet: (Vlan Z)

3rd Subnet

Network ID            : 172.16.12.0

1^st Host ID             : 172.16.12.1

Last Host ID              : 172.16.15.254

Broadcast ID             : 172.16.15.255

Subnet Mask             : 255.255.252.0

Example 2: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP                           : 172.16.0.130

Subnet Mask         : 255.255.255.128

Find Network ID?

Answer:

Subnet Mask is used to find Network & Host bit 

IP and Subnet Mask in Binary

For Network ID, Make Host as zero

Make Host as 0's

172.16.0.128 is Network ID

Example 1: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

Example 1

v  In NITT Campus,

For Admin we need 100 Host (Vlan name – Vlan A)

For Security – 100 Host (Vlan B)

Dean – 100 Host (Vlan C)

So totally we need 300 Host

Answer:

v  If we choose Class C, Last bit only Host. So we can choose maximum 255 Host only, but we need 300 Host. So we choose Class-B or Class-A

v Now We Choose Class-B to Solve

Sub-netting

v  We Never Use 0^th Subnet

1^st Subnet: (Vlan A)

1st Subnet

N/w ID: 172.16.0.128

1^st Host ID: 172.16.0.129

Last Host ID: 172.16.0.254

Broadcast ID: 172.16.0.255

Subnet Mask: 255.255.255.128

2^nd Subnet: (Vlan B)

2nd Subnet

N/w ID: 172.16.1.0

 (Previous Vlan next broadcast IP is this Vlan network id)

1^st Host ID: 172.16.1.1

Last Host ID: 172.16.1.126

Broadcast ID: 172.16.1.127

Subnet Mask: 255.255.255.128

3^rd Subnet: (Vlan C)

3rd Subnet

N/w ID: 172.16.1.128

1^st Host ID: 172.16.1.129

Last Host ID: 172.16.1.254

Broadcast ID: 172.16.1.255

Subnet Mask: 255.255.255.128