Ccna - vlsm

supertech10

- I need your help me regarding ccna.

- I want to ask about vlsm.

- vlsm is one of method in subnetting (diving large network into smaller network).

- the formula that use in vlsm is 2^h>=our requirement where h represent number of host bits used.

- binary (0,1) also cover in vlsm. why binary (0,1) need in vlsm. for example:-

There is six office want to allocate different amount of ip address for 150.150.0.0 and work sum show below:-

150.150.0.0

Subnet Mask: 255.255.0.0

Net ID: 16 bit

Host ID: 16 bit


First Office – 100 IP Address

2^H>=100

2^7>=100

Subnet Mask: 255.255.255.128

Net ID: 25 bit

Host: 7 bit

Net ID: 150.150.00000000.0 0000000 = 150.150.0.0

First Host: 150.150.00000000.0 0000001 = 150.150.0.1

Last Host: 150.150.00000000.0 1111110 = 150.150.0.126

Broadcast IP: 150.150.00000000.0 1111111 = 150.150.0.127


Second Office – 50 IP Address

2^H>=50

2^6>=50

Subnet Mask: 255.255.255.192

Net ID: 26 bit

Host: 6 bit

Net ID: 150.150.00000000.10 000000 = 150.150.0.128 0,1,10

First Host: 150.150.00000000.10 000001 = 150.150.0.129

Last Host: 150.150.00000000.10 111110 = 150.150.0.190

Broadcast IP: 150.150.00000000.10 111111 = 150.150.0.191


Third Office – 25 IP Address

2^H>=25

2^5>=25

Subnet Mask: 255.255.255.224

Net ID: 27 bit

Host: 5 bit

Net ID: 150.150.00000000.110 00000 = 150.150.0.192

First Host: 150.150.00000000.110 00001 = 150.150.0.193

Last Host: 150.150.00000000.110 11110 = 150.150.0.222

Broadcast IP: 150.150.00000000.110 11111= 150.150.0.223


Fourth Office – 13 IP Address

2^H>=13

2^4>=13

Subnet Mask: 255.255.255.240

Net ID: 28 bit

Host: 4 bit

Net ID: 150.150.00000000.1110 0000 = 150.150.0.224

First Host: 150.150.00000000.1110 0001 = 150.150.0.225

Last Host: 150.150.00000000.1110 1110 = 150.150.0.238

Broadcast IP: 150.150.00000000.1110 1111= 150.150.0.239


Fifth Office – 8 IP Address

2^H>=8

2^3>=8

Subnet Mask: 255.255.255.248

Net ID: 29 bit

Host: 3 bit

Net ID: 150.150.00000000.11110 000 = 150.150.0.240

First Host: 150.150.00000000.11110 001 = 150.150.0.241

Last Host: 150.150.00000000.11110 110 = 150.150.0.246

Broadcast IP: 150.150.00000000.11110 111= 150.150.0.247


Sixth Office – 4 IP Address

2^H>=4

2^2>=4

Subnet Mask: 255.255.255.252

Net ID: 30 bit

Host: 2 bit

Net ID: 150.150.00000000.111110 00 = 150.150.0.248

First Host: 150.150.00000000.111110 01 = 150.150.0.249

Last Host: 150.150.00000000.111110 00 = 150.150.0.248

Broadcast IP: 150.150.00000000.111110 11= 150.150.0.251


- in first office, net id show as 150.150.00000000.0 0000000

- after that, in second office net id show as 150.150.00000000.10 000000

- for that, I want to know why binary (0,1) use in net id of first office till sixth office?

Jon_Cisco

To much info not enough detain in the question.
Can you expand your question to be a little more specific?


- for that, I want to know why binary (0,1) use in net id of first office till sixth office?

I'm not really sure what you are asking about here except maybe how the subnet mask is determined.
Using a mask of 128 = 1000 0000 in binary and this mask allows 126 hosts
Using a mask of 192 = 1100 0000 in binary and this mask allows 62 hosts

I'm not really sure thats the information your looking for but maybe it will get you started.
Posted this quick so I hope I didn't make any mistakes.

Good Luck!

richypc

Fifth Office – 8 IP Address

Subnet Mask: 255.255.255.240 = 14 usable IP address

Net ID: 150.150.0.240

First Host: 150.150.0.241

Last Host: 150.150.0.254

Broadcast IP: 150.150.0.255




Sixth Office – 4 IP Address
Subnet Mask: 255.255.255.248 = 6 usable IP addresses


Net ID: = 150.150.0.248

First Host: = 150.150.0.249

Last Host: = 150.150.0.254

Broadcast IP: = 150.150.0.255