What are IP addresses, subnet masks, gateways, DNS? What s the difference?

IP address is the specific location of the house number, which is composed of up to 12 digits, such as the most common and so on.

A subnet mask is a 32-bit address that masks part of an IP address to distinguish between network and host identities and to indicate whether the IP address is on a LAN or a remote network, as if it were a zip code.

The gateway is a facility that operates on top of the OSI transportation layer in the interconnection network, for example, we usually like to use one machine as the host, and the other ones are connected in series to go to the Internet together, so this host is the gateway.

DNS is the domain name resolution server, that is, when you go online, you are all input.

Such a domain name and the real address of ** is in the form of an IP address, due to memory trouble, there is a domain name instead of DNS, which is the form of converting the domain name into an IP address As for the first choice of DNS, because there is a problem of network speed on the network, so when you go online, your request command first passes through the nearest DNS server to you, which is usually the best network speed, this is the first DNS, but when there is a problem with your line, Then you have to go to another DNS server that is far away from you, and this is the backup DNS.

As for the difference, their roles are different, each one is useful, and one less is not enough.

The IP address is the house number.

The subnet mask is the cell zip code that determines the number and size of the subnet.

The gateway is the post office, between the various networks.

I guess that's how it can be understood.

First of all, check the extranet.

Subnet mask, gateway, DNS information.

2. If it is broadband Internet access, select the broadband dialing form in the WAN port settings, and enter the broadband and password provided by the network service provider. After the dial-up is successful, the IP address, subnet mask, NMS, and DNS information are automatically obtained.

3. Intranet. The address pool only needs to be set: the IP network segment, which is generally the first IP of the network segment, such as the subnet mask changes according to the requirements of the intranet) gateway, DNS can be set or set to local operator DNS.

IP address, which identifies the identity of your computer. The subnet mask can indicate the subnet division, which belongs to the split subnet. The default gateway, the default egress of the packet, is generally your router address.

To put it simply, the subnet mask is to determine whether two IP addresses are in the same network segment (or subnet), and two addresses in the same network segment can communicate directly.

Whether it's by IP address or "computer name", it's fine. If the two IP addresses are not in the same network segment, the gateway address is required to access the computer (also the IP address) of the other network segment through the IP address.

The gateway address is the egress address, and the gateway address is the address of the most recent egress you have. The gateway address is always the same network segment as your computer's IP address.

IP address classification.

1. Class A IP address.

A Class A IP address refers to, or shout out of the four segments of the IP address, the first segment number is the network number, and the remaining three segments are the local computer number. The length of the network identity in the Class A IP address is 8 bits, and the length of the host ID is 24 bits, and the number of Class A network addresses is small, which can be used in large networks with more than 16 million hosts.

2. Class B IP address.

A Class B IP address is one in which the first two segments of the four segments of the IP address are network numbers. The length of the network identity in the Class B IP address is 16 bits, and the length of the host ID is 16 bits, and the Class B network address is suitable for medium-sized networks, and the number of computers that can be accommodated in each network is more than 60,000.

3. Class C IP address.

Among the four segments of an IP address, the first three segments are network numbers, and the remaining numbers are local computer numbers. The length of the network identity in the Class C IP address is 24 bits, and the length of the host ID is 8 bits, and the number of Class C network addresses is large, which is suitable for small-scale local area networks, and each network can only contain a maximum of 254 computers.