What does domain name resolution mean? How does domain name resolution work?

What does domain name resolution mean? How to operate domain name resolution? Domain name resolution is the process of converting domain names to IP addresses. Domain names are a set of address conversion systems specially established for the convenience of everyone's memory. If users want to access a server on the Internet, they must use IP addresses in the end. Domain name resolution is the process of converting domain names back to IP addresses. The resolution of domain names is completed by intelligent DNS servers.

What is IP reverse resolution?

There are two areas in the DNS server, namely "forward lookup area" and "reverse lookup area". The forward lookup area is the domain name resolution mentioned by the editor before, and the reverse lookup area is IP reverse resolution. Its function is to obtain the domain name pointed to by the IP address by querying the PTR record of the IP address. Of course, to successfully obtain the domain name, the PTR record of the IP address must be available. PTR records are a type of mail exchange records. There are A records and PTR records in mail exchange records. A records resolve names to addresses, while PTR records resolve addresses to names. Address refers to the IP address of a client, and name refers to the fully qualified domain name of a customer. By querying the PTR record, the purpose of reverse query is achieved, which is why everyone can use the IP address to find the domain name Whois information.

What is an A record?

A (Address) record is used to specify the IP address record corresponding to the host name (or domain name). Users can point the website server under the domain name to their own web server. At the same time, you can also set the second-level domain name of your domain name.

What is an MX record?

Mail routing record, users can point the mail server under the domain name to their own mail server, and then they can control all the mailbox settings by themselves. You only need to fill in the IP address of your server online to transfer all the mail under your domain name to the corresponding mail server you set yourself.

The function of the reverse domain name resolution system (Reverse DNS) ensures that the appropriate mail exchange records are effective. This is the most common problem (especially for foreign mail systems). More email providers use reverse DNS lookups to confirm where the information comes from. As this method becomes more widely used, domains that do not correctly publish reverse DNS information may have more frequent mail bounces. Therefore, after the forward domain name resolution is completed, you should also apply to your line access provider (ISP) for reverse address resolution, especially for foreign corporate emails, to reduce the possibility of being bounced by foreign institutions.

The reverse domain name resolution verification is actually performed by the other party's server. If we do not perform reverse resolution, the reverse resolution verification of the other party's server will fail. In this way, the other party's server will refuse to receive our emails as unknown senders. This is why we cannot send emails to the mail server without performing reverse resolution after excluding other reasons (such as being blacklisted by the other party, no MX records, using a dynamic IP address, etc.).