What is China Unicom's dns address?

China Unicom has two dns addresses. The primary DNS is "210.21.4.130" and the backup DNS is "221.5.88.88". Each IP address can have a host name, and the host name consists of one or more It consists of strings separated by decimal points.

For Unicom broadband users, the primary DNS is set to: 210.21.4.130, and the backup DNS is: 221.5.88.88.

Each IP address can have a host name. The host name consists of one or more strings separated by decimal points. With the host name, don't memorize the IP address of each IP device by rote. Just remember the host name that is relatively intuitive and meaningful. This is what the DNS protocol does.

Extended information
There are two ways to map host name to IP address:

1) Static mapping, each device is configured with mapping from host to IP address. Each device independently maintains its own mapping table, which is only used by this device;

2) Dynamic mapping, establish a domain name resolution system (DNS), and only configure the host to IP address on a dedicated DNS server Mapping, devices on the network that need to communicate using host names first need to query the DNS server for the IP address corresponding to the host.

The process of finally obtaining the IP address corresponding to the host name through the host name is called domain name resolution (or host name resolution). When resolving a domain name, you can first use the static domain name resolution method. If the static domain name resolution fails, then use the dynamic domain name resolution method. Some commonly used domain names can be put into the static domain name resolution table, which can greatly improve the efficiency of domain name resolution.

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