How to determine whether the computer belongs to the same network segment and whether the computer b

IP addresses alone cannot accurately determine whether they are on the same network segment.

The logical address of the host is represented by the IP address along with the subnet mask.

The above omits some things, what is the host ID, it is taken from the 8-bit host number and the 3-bit subnet number.

and are both Class C IPs, if you don't specify the subnet mask, press the default subnet mask that andand are all in the same network segment.

To be exact. and in the same network segment.

and are not in the same CIDR block.

You can't tell if it's the same network segment by IP alone!

For example: with.

In the absence of a mask, everyone will definitely feel that they are in the same network segment! But what if so?

With the AND algorithm it is clear that they are not in the same network segment!

There's something wrong with what you're saying. The host is identified as 00000101 ?? What does this mean?

The host ID should be 101, 00101, or 000101. There is a mistake in the statement. Just because it's 0 doesn't mean it's the host ID.

It depends on how people decide.

To determine whether it is the same network segment, it is necessary to use the IP and subnet mask to do the same operation, and the 00 of the mask is the network ID, as long as the network ID is the same, it is the same network segment.

If you want to be in the same network segment, you must have the same network identity, so how to calculate the network identity?

The network identification algorithm of each type of IP is different.

Category A, only the first paragraph is counted.

Category B, only counting.

Paragraphs 1 and 2. Category C, counted.

Paragraphs 1, 2 and 3.

The algorithm only needs to put the digits of the IP and subnet masks and.

and methods: 0 and 1 0 0 and 0 0 1 and 1 1 such as: and,, first convert to binary, and then and every bit of the IP

Subnet mask. Derive and results.

Convert to decimal system, which is the network identity, and then reverse the subnet mask, that is:

With ip and get the result:

Convert to decimal system, i.e., that's the host ID.

In order to be on the same network segment, the network identity must be the same.

Let's take a look at the Class B IP that has been changed to the default subnet mask, such as ip:,, and the subnet mask are all set to, in the same network segment?

Convert these into binary first.

and, respectively, got.

The network identifier is different, that is, it is not in the same network segment.

The same network segment means that the IP address and subnet mask are matched to obtain the same network address.

Devices that often use the same physical layer must be directly connected to each other through the same transmission medium, but if two groups of network devices whose transmission media are not directly connected, if their transmission media are connected through extension devices such as repeaters and hubs working in the physical layer, they are still regarded as devices in the same physical layer, and one network segment instead of two.

1. Subnet mask.

is a 32-bit address, and the subnet mask is used to mask the IP address.

to distinguish between the network identity and the host identity, and to indicate whether the IP address is on a local area network or a remote network. The general IP address settings are as follows.

2. The method of finding the network identity is as follows: binary the subnet mask.

Binary to IP address "AND".

<>4. To determine whether the two IP addresses are in the same network segment, it is to compare the network identifier (network address, if the network identifier is the same, it is in the same subnet, otherwise, it is not in the same subnet.

The subnet mask is all 16-bit, that is. The first 24 bits of both IPs are the same, so they are on the same network segment.

The subnet masks are all 24-bit, that is. The first 24 bits of the two IPs are not the same, one is the other is not the same segment.

One subnet mask is 16-bit and the other is 24-bit. At this time, it is the same network segment as it. And for the pair and it is not a network segment.

1. The same network segment in the network refers to the same network address obtained by matching the IP address and subnet mask.

2. If you want to be in the same network segment, you must have the same network identification. The network identification algorithm of each type of IP is different and needs to be judged based on the number of bits in the subnet mask.

3. Network Identification Algorithm:

1. Just put the digits of the IP and subnet mask and that's it.

2. and method: 0 and 1 = 0 0 0 and 0 = 0 1 and 1 = 13, such as: and ,, first convert to binary, and then and every bit.

IP subnet mask.

Derive and results.

4. Convert to decimal system, which is the network identity.

5. Then reverse the subnet mask, that is, with IP and6, get the result, and convert it to decimal system, that is, this is the host ID. In order to be on the same network segment, the network identity must be the same.