Five types of questions about network planning

Five types of questions

Suppose a host IP The address is 192.168.5.121, The subnet mask is 255.255.255.248, What is the network number of the host ？

Explain ： Subnet mask ： 11111111  11111111  11111111  11111000
         host IP Address ： 11000000  10101000  00000101  01111001
         Phase sum operation ：     192.168.5.（01111000）=120
         The final network number is 192.168.5.120

Of a computer IP The address is 208.37.62.23, If the address mask of the network is 255.255.255.240, Then the network
Up to （ ） Subnet , Each subnet has a maximum of （ ） Console host

Explain ： Address mask （ Subnet mask ） The first three 255 All binary numbers are 1,240 The binary number of is 1111 0000
And IP Address （208.37.62. 0001 0111） Perform phase and operation to get 208.37.62.(0001  0000), The number of hosts is 2 Of 4 Power （ The host binary digits are 4 position ） Subtract all 0 And all 1 be equal to 14
Similarly, each subnet is 2 The fourth power of -2=14（ Console host ）

namely 16 Subnet ,14 Console host .

When A Class network address 34.0.0.0 Use 8 When binary bits are used as subnet addresses , The subnet mask is set to ？

Explain ：
The first thing to know is a Class address default subnet mask 255.0.0.0 b class 255.255.0.0 c class 255.255.255.0
So the title is A Class network address , Is to tell you that its default subnet mask is 255.0.0.0
It says to use 8 Bit binary bit as subnet address , Description is to follow the last non-zero bit 8 individual 0 Set up 1,
That is to say 255.255.0.0
So the answer is 255.255.0.0.

    

A department applied to a C class IP Address , To divide into 6 Subnet , The mask should be ？

Explain ：C class IP The default subnet mask of the address is 255.255.255.0
If you want to share 6 Subnet , There should be 2 The third power of =8 Just enough points
So the last host number should be 1110 0000 =224
Mask ：255.255.255.224

If the subnet mask is 255.255.255.192（1100 0000）, The following IP Which address belongs to the same subnet

Explain ： Match the subnet mask to the host IP Address and get their respective network numbers , See if the two options are in the same subnet
such as 156.26.27.（71= 0100 0111） and 156.26.27.（110= 0110 1110）
The last two results of the phase and operation ：156.26.27.（0100 0000） and 156.28.27.（0100 0000）
The two are the same , So on the same subnet .