What does dns exception mean?

Dns exception means that the server is faulty and the server's address cannot be found. DNS is a server that converts domain names and corresponding IP addresses. DNS stores a table of domain names and corresponding IP addresses to resolve domain names; this eliminates the need to memorize each domain name by rote. For the IP address of the IP device, just remember the relatively intuitive and meaningful host name.

#The operating environment of this article: Windows 7 system, Dell G3 computer.

DNS is a server that converts domain names and corresponding IP addresses. DNS stores a table of domain names and corresponding IP addresses to resolve domain names.

DNS service exceptionIt means that the server is faulty and the address of the server cannot be found.

Importance of DNS

• Technical perspective

  DNS resolution is the actual addressing method for most applications on the Internet; The further development of domain name technology and various applications based on domain name technology have enriched Internet applications and protocols.

• From a resource perspective

  Domain name is an identity mark on the Internet and a unique identification resource that cannot be repeated; the globalization of the Internet has made domain names a symbol of a country’s sovereignty. strategic resources.

DNS main functions

Each IP address can have a host name, and the host name is given by It 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.

There are two ways of mapping host name to IP address:

1) Static mapping, each device is configured with mapping from host to IP address, and each device independently maintains its own mapping table , and only for use by this device;

2) Dynamic mapping, establish a domain name resolution system (DNS), only configure the mapping from the host to the IP address on the dedicated DNS server, the host name needs to be used on the network The communication device first needs 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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