What is DNS query? The principle and function of DNS query are explained in detail

in daily network access, we only need to enter the familiar domain name to open the corresponding website, which is inseparable from a set of automatic network mechanism support, of which DNS query is one of the core links. Many users have no perception of its existence, but it directly determines the speed and stability of network access. This article will disassemble the relevant knowledge of DNS query in detail from the basic concepts, operating principles, core functions and other dimensions, so that you can thoroughly understand this hidden behind the network key technology.

What is the basic definition of DNS query?

to understand the role of DNS queries, we must first clarify its core definition and essential properties.

1, the core essence of DNS query

DNS query is the core operation of the domain name system, which is essentially the process of converting the user-entered easy-to-remember domain name into the Internet Protocol Address that can be recognized by the network device. Because the devices in the network can only communicate through the Internet Protocol Address, and the domain name is designed to facilitate human memory, DNS query acts as a translator between the two.

2, DNS query trigger scenarios

DNS query will be automatically triggered in a variety of scenarios, such as when the user clicks access when entering the domain name in the browser, or when the device first accesses a domain name after connecting to the network, or even when the local DNS cache expires and then accesses the domain name again, it will automatically initiate DNS query request.

What is the operating principle of DNS query?

DNS query is a hierarchical and progressive query process, which involves the cooperative work of multiple network nodes.

1 and DNS queries

when a user initiates a network access request, the device will first check the local DNS cache. If there is an Internet Protocol Address record for the corresponding domain name in the cache, it will directly return the result without initiating an external DNS query. This is also the fastest query path. The local cache is usually saved for a period of time, and the query will be restarted after the valid period.

2, recursive iterative process of DNS query

if there is no corresponding record in the local cache, the device will initiate a recursive query request to the local DNS server. The local DNS server will first check its own cache. If there is no result, it will initiate an iterative query to the root domain name server. The root server directs to the top-level domain server, and the top-level domain server directs to the authoritative domain name server. Finally, get the Internet Protocol Address and return it to the user device.

What are the core functions of DNS queries?

DNS query is not just a simple address translation, it plays several key roles in the network ecosystem.

1, to achieve efficient conversion of domain names and IP

this is the most basic and core role of DNS query, which solves the contradiction between human memory difficulties and device communication needs. Users do not need to remember complex Internet Protocol Address, just enter a simple and easy to remember domain name, DNS query can quickly complete the conversion, making network access simple and convenient.

2, to ensure the stability of network access

DNS query can also improve network stability through intelligent resolution, when a server corresponding to an Internet Protocol Address fails, the authoritative DNS server can domain name resolution to the Internet Protocol Address of the standby server, and the user can obtain the available IP when initiating a DNS query.

How to optimize the efficiency of DNS queries?

for the running characteristics of DNS queries, we can optimize their efficiency and improve network access speed in many ways.

1, adjust the local DNS cache duration

reasonably set the valid period of the local DNS cache, it can not only avoid frequent DNS queries occupying network resources, but also ensure the timeliness of domain name resolution records. Generally speaking, the cache time of commonly used domain names can be set to about 24 hours, and the time can be appropriately shortened for uncommon domain names.

2, choose a high-quality public DNS server

the performance of the public DNS server directly affects the speed of DNS queries, selecting a public DNS server with many nodes and sufficient bandwidth can greatly shorten the query response time. At the same time, high-quality public DNS servers can also provide anti-hijacking services to avoid DNS queries being maliciously tampered with to cause abnormal access.

sum up, DNS query is an indispensable core link in the network access process. It is based on domain name and IP conversion, and provides users with convenient and stable network access services through a hierarchical recursive operation mechanism. At the same time, through reasonable optimization means, it can further improve the efficiency of DNS query and make the network experience smoother. Whether it is ordinary users or network operation and maintenance personnel, understanding the relevant knowledge of DNS query can better protect their own network experience.