How to question a DNS server ?

Name resolution is essential to the proper functioning of the web. The operation makes it possible to translate complex network addresses into simple terms adapted to Internet users. However, it is sometimes necessary to use an IP address in the event of failures of this system.

This technique also promotes authentication of the target web server and detection of any DNS redirection.

How does the DNS server work ?

THE Dns is one of the elements that have contributed to the expansion and success of the web. Indeed, the system has facilitated network membership and the use of this technology. What is a DNS ? The Name System Domaine is a distributed service that can be considered as a directory for computers.

This non-centralized model has also contributed to its integration into the basic protocols of the Internet.

Like the classic directory, the DNS relates names and coordinates. However, it associates domain names and IP addresses of servers. These two information constitutes the DNS records.

Given the number of connected hosts, the network would have been affected by the centralization of this data. The system has thus Distributed the registers between areas, sub-domains and DNS zones.

Concretely, the virtual internet repertoire is managed by a myriad of servers around the world. All network computers can Ask a DNS server To find out a domain name or IP address. If he does not find this information, he will in turn question names of another level.

So, he will bring back the initial DNS requests in the authority of authority.

If there is no match, the request will be forwarded to the authoritative server in the domain. Administrators are responsible at this level for managing the DNS zone (aliases, IP addresses, DNS servers, etc.). In particular, they can modify, delete or add entries in the master server.

For their part, the slave servers only have copies of these zone files.

How to find your server ?

Before’query a DNS server, it’s important to check your connection settings. This initiative makes it possible to analyze your local network, your default gateways, your IPv4 and IPv6 addresses, etc. The approach is also essential, if you have decided to configure a DNS server per device (PC, mobile, router, etc.).). In this case, it is quite difficult to identify the priority settings.

To be fixed, use the function “ ipconfig » executable from Windows Command Prompt. In addition, the necessary line is easy to remember. Just write ” IPCONFIG /ALL »To get all the details on your DNS server.

If you make a typo, CMD will automatically display the help section with a list of exact formulas. Select the command, Copy, Paste and type on Entry.

You can also enter ” ipconfig »To obtain a summary of the configuration of your internet protocol. The results will contain the name and address of the DNS server of your system. If you are not familiar with CMD, favor the Window+R keyboard shortcut to launch the Running tool. Write ” cmd ” And validate (Enter key or button OK).

The command prompt will then appear in the foreground.

Finally, there are third -party applications to check the mobile name server on Android or iOS. Many can be downloaded for free on the Play Store or the App Store. These tools are notably useful, if you cannot recognize the DNS server of your Internet access provider (ISP).

Indeed, your connected devices will be configured by default according to the DNS configuration of the Wi-Fi.

How to find your server?

How to query a DNS server ?

nslookup is the program par excellence for query a DNS server on most operating systems. The function is also offered natively on Windows, macOS and Linux distributions. However, the developers recommend prefer “dig” or “host” for type OS Unix.

In any case, these three tools make it possible to find information on the DNS.

host » is concise and easy to understand. To find an IP address, just enter in the terminal: $ host [domain name]. The Unix utility also covers reverse DNS.

This time, you will need to enter: $ host [IP address]. The corresponding host will be displayed on the next line. “dig” also works in command line. His name comes from the English “Domain Information Groper”.

This UNIX customer is available in “dnsutils” packages for Linux and “Bind Utils” for Fedora. To request a basic DNS recording, launch the line:

# DIG [Domain name]. This request refers to the IP address of the target field. You can also add specifications for other types of records. You will have thus:

# DIG [Domain name] (+shorts, MX, TTL, SOA, etc.).

Finally, ” nslookup »Allows you to send specific messaging type requests (MX), Pointer (PTR), Start of Authority (SOA)… You will simply receive an IP address with the command: NSLOOKUP [Domain name]. For a specified field, go to the line after each entry:

>Set type = [IPv4, IPv6, SOA, MX, NS, PTR, etc.

After the activation of “Nslookup”, do not hesitate to launch the “Help” command to discover all the associated features.