A superficial understanding of P and subnet masks

, as we all know, IP is made up of four numbers. Here, let’s first take a look at the 3 commonly used IP:

class A, IP, 0.0.0.0 to 127.255.255.255

B class IP segment 128.0.0.0 to 191.255.255.255

C class IP segment 192.0.0.0 to 223.255.255.255

The subnet mask assigned by

XP by default is only 255 or 0

per segment

class a default subnet mask 255.0.0.0. A subnet can hold up to more than 16 million 770 thousand computers at most,

The default subnet mask 255.255.0.0 for the

B class. A subnet can hold up to 60 thousand computers at most,

The default subnet mask 255.255.255.0 for the

C class. A subnet can hold up to 254 computers at most,

I used to think that in order to put some computers in the same network segment, as long as the first three sections of IP are OK, today I realized I was wrong. If I say this, a subnet can only accommodate 254 computers, it’s a bit of a joke. Let’s take a closer look at it.

in the same network segment, as long as the network identifier is the same, how do you see the network identification? First thing is to convert each segment of IP into binary. (someone says, "I don’t change" Yeah, that’s OK. We use Windows to bring our calculator. Open the calculator, check the >, scientific, enter decimal numbers, and then click "binary" this radio point, you can switch to binary.

)

sub network mask switching to binary, we will find that all the subnet mask is composed of 0 by a string of [red] continuous [/red] 1 and a string of [red] [/red]’s (a total of 4 sections, each section 8, a total of 32 digits).

255.0.0.0 11111111.00000000.00000000.00000000

255.255.0.0 11111111.11111111.00000000.00000000

255.255.255.0 11111111.11111111.11111111.00000000

this is the binary form of the default subnet mask for the A/B/C three class. In fact, there are many seed mesh masks, as long as it’s a series of 1 and a series of 0. Such as 11111111.11111111.11111000.00000000, this is also a passage

Leave a Reply

Your email address will not be published. Required fields are marked *