Large-scale network IP planning

 

Requirements:

 

1. Scientific

 

2. Rationality

 

3. scalability

 

4. Ease of Management

 

 

 

Data: Binary: 128 64 32 16 8 4 2 1

 

11111111.111111.111111111111.111111

 

Case: A university now needs to build a network. In order to facilitate the management of school information center personnel, a reasonable IP address plan is required. Currently, 15 schools and one school leader domain are available, A total of 16 subnets need to be built and the IP addresses of 2000 PC machines need to be set in each school. Now, half of the IP addresses need to be reserved in advance for future network expansion. Assume that each school needs to set up eight school subnets (for example, data center 1, Data Center 1, Data Center 3, laboratories, research rooms, school leader's network, and graduate students) to facilitate the management of the school departments. The IP address is expected to be configured at network ID 172.16.0.0/16.

 

Analysis: 1. 16 second-level subnets

 

2. 2000 IP addresses per Subnet

 

3. Each second-level subnet is divided into eight third-level subnets (with over 256 machines)

 

4. network ID: 10101100.0002.16.00000000.00000000

 

Subnet Mask: 11111111.111111.20.2.16.00000000

 

Solution:

 

1. Now we need to reserve half of the IP addresses: we need to set a level-1 subnet to reserve half of the IP addresses of the network:

 

(1) The network number in the current network ID is: 172.16 (16 bits) The host number is 0.0 (16 bits)

 

Number of hosts: 16 to the power of 2

 

(2) If you want to split the host number in the network ID into two, borrow one from the host number and change it to the network number. Now, it is changed to two primary subnets: 172.16.0.0/17 172.16.128.0/17. The interval between network numbers is 27 = 128 (7 indicates the number of hosts in the third group)

 

Level 1 subnet network. 0002.16.00000000.000000000000

 

Level 1 subnet network. 0002.16.0000000.00000000

 

Subnet Mask: 11111111.111111.0000000.00000000

 

Now the network number in each sub-network is: 17-bit host number is 15

 

Number of hosts: 215

 

(3) reserve the first-level subnet 1: 172.16.0.0 and allocate the first-level subnet 2: 172.16.128.0.

 

2. Now, in the first-level subnet 2: 172.16.128.0, 16 second-level subnets are divided. Each second-level subnet has more than 2000 machines,

 

(1) The network number in the current network ID is: 172.16.128 (17-bit) host number: 15

 

Number of hosts: 215

 

(2) To divide 16 second-level subnets on the first-level subnet, you must borrow four (24 = 16) digits from the host number to change the network number into 16 second-level subnets, the interval between network numbers is 23 = 8 (3 indicates the number of hosts in the third group)

 

Second-level subnet network. 0002.16.0000000.00000000 172.16.128.0/21

 

Second-level subnet network. 0002.16.10001000.00000000 172.16.136.0/21

 

Second-level subnet network. 0002.16.1002.16.00000000 172.16.144.0/21

 

Secondary subnet network. 0002.16.10011000.00000000 172.16.152.0/21

 

Second-level subnet network. 0002.16.102.160.00000000 172.16.160.0/21

 

Second-level subnet network. 0002.16.10101000.00000000 172.16.168.0/21

 

Second-level subnet network. 0002.16.10112.16.00000000 172.16.176.0/21

 

Second-level subnet network. 0002.16.10111000.00000000 172.16.184.0/21

 

Secondary subnet network. 0002.16.112.1600.00000000 172.16.192.0/21

 

Second-level subnet network. 0002.16.11001000.00000000 172.16.200.0/21

 

Second-level subnet network. 0002.16.1102.16.00000000 172.16.208.0/21

 

Second-level subnet network. 0002.16.11011000.00000000 172.16.216.0/21

 

Second-level subnet network. 0002.16.112.160.00000000 172.16.224.0/21

 

Second-level subnet network. 0002.16.11101000.00000000 172.16.232.0/21

 

Second-level subnet network. 0002.16.11112.16.00000000 172.16.240.0/21

 

Second-level subnet network. 0002.16.11111000.00000000 172.16.248.0/21

 

Subnet Mask: 11111111.111111.11111000.00000000

 

The network number in each sub-network is: 21-bit host number is 11

 

Number of hosts: 211 (2048)

 

Currently, there are a total of 2048 IP addresses in the host number, except the network number and broadcast number, which are sufficient to meet the requirements in the solution.

 

(3) now the second-level subnet 1: 172.16.128.0/21 is used as an example to divide the third-level subnet to meet the requirements of the school.

 

3. Now there are three level-3 subnets in the second-level subnet 1: 172.16.128.0/21. Each level-3 subnet has more than 256 machines,

 

(1) The network number in the current network ID is: 172.16.128 (21 bits) host number: 11 bits

 

Number of hosts: 211

 

(2) To divide eight three-level subnets on the second-level subnet, You need to borrow three (23 = 16) digits from the host number to change the network number into eight three-level subnets, the interval between network numbers is 20 = 1 (0 indicates the number of hosts in the third group)

 

Level 3 subnet network. 0002.16.0000000.00000000 172.16.128.0/24

 

Level 3 subnet network. 0002.16.0000001.00000000 172.16.129.0/24

 

L3 subnet network. 0002.16.10000010.00000000 172.16.130.0/24

 

L3 subnet network. 0002.16.10000011.00000000 172.16.131.0/24

 

L3 subnet network. 0002.16.0000100.00000000 172.16.132.0/24

 

L3 subnet network. 0002.16.0000101.00000000 172.16.133.0/24

 

L3 subnet network. 0002.16.20.110.00000000 172.16.134.0/24

 

L3 subnet network. 0002.16.2017111.00000000 172.16.135.0/24

 

Subnet Mask: 11111111.111111.11111111.00000000

 

The network number in each sub-network is: the 24-bit host number is 8

 

Number of hosts: 28 (256)

 

Currently, there are a total of 256 IP addresses in the host number, except the network number and broadcast number, which are sufficient to meet the requirements in the solution.

 

Take dividing three level-3 subnets in the second-level subnet 1: 172.16.128.0/21 as an example to divide the middle-level and third-level subnets of the school. The other second-level subnets are divided by the above methods.

 

 

 

Now the IP addresses of this large network are reasonably and scientifically configured. If you expand the Department or add a department in the future, you only need to extract the corresponding IP address from the reserved level-1 subnetwork. If the Department's IP address is not enough, you can also extract the corresponding IP address from the reserved level-1 subnetwork. Same principle.

 

Note: The first-level subnet network, second-level subnet network, and third-level subnet network in this article are designed to facilitate understanding of IP planning ideas! They are collectively referred to as subnets!

 

From: jthappy's BLOG