Term Explanation: Domain Resolving; A Record; MX Record; CNAME Record; TTL

  1. What is domain resolving?
    Domain resolving is actually the converting process of tying text-based domain names to the numeric IP Addresses that are necessary to locate the domain name’s server on the net. For the convenience of memory, IP addresses are replaced by domain names to identify the websites. The resolving of domains is done by DNS servers.
  2. What is A record?
    A (Address) record is the corresponding IP address used to specify hostname (or domain name). You can point the website servers under your appropriate domain to your own web servers and setup sub-domains for your domains at the same time.
  3. What is MX record?
    MX record is the mail exchange record. You may point your mail server under your appropriate domain names to your own mail server, and manage all the mail settings by yourself. Just fill in the IP address of your server online, it will help you forward all the emails under your appropriate domain name to your own mail server.
  4. What is CNAME Record?
    CNAME is canonical name record. Such record allows you to map more than one name to the same computer and it is generally applying to the computers offering web and email services on the same one. For example, there is a computer named ‘host.mydomain.com’ (A record) offering both www and mail services. For the users’ convenience to access the websites, you can give two CNAME to the computer: www and mail. The full names of these two aliases are www.mydomain.com and mail.mydomain.com, actually both of them are pointing to host.mydomain.com.
  5. What is the TTL?
    The full name of TTL is "Time To live". In short, it refers to the keeping time of DNS record at DNS server. Below is an example to explain what is TTL’s value.
  6. Supposing there is a domain myhost.abc.com (Actually this is a DNS record, it generally means that there is a host computer called myhost in the domain abc.com). its corresponding IP address is, and its TTL is 10 minutes. This domain or this record is kept in a DNS server called dns.abc.com.
  7. Now if an user inputs the following address (or URL): http://myhost.abc.com, what will happen next?
  8. The DNS server appointed by the user (or the DNS assigned automatically by his ISP, network provider) will try to explain him myhost.abc.com, surely the DNS server can’t resolve right away since it doesn’t include the records of myhost.abc.com. But through the recursive search of DNS in the world, it finally goes to the server dns.abc.com.
  9. The DNS server dns.abc.com informs the DNS server the corresponding IP address of myhost.abc.com, and then informs the user of the result. To speed up the resolving of this record, will keep the result for a period of time, that is called TTL time. In this period, if the user requests to resolve myhost.abc.com again, will tell the user directly. While if the TTL time is outdated, the whole process will be repeated.

What kinds of domain name can be supported by DNS-DIY?

Except for multilingual domain names, any domain names registered by us. can be resolved by DNS-DIY online. Such as, .com, .net, .org, .biz, .info, .name, .cn, .us, .cc, .tv, etc.

Why is my domain name resolving not active?

The following reasons may cause your domain resolving not to take effect.

  1. The domain name’s DNS is not configured to the correct DNS as requested. Please make sure that the DNS are ns1.dns-diy.com and ns2.dns-diy.com, or the IP addresses of the DNS are the same as ns1.dns-diy.com or/and ns2.dns-diy.com.
  2. There’re not any record for the domain name.

How to check whether the name servers have been setup as valid ones?

You can check whether the DNS has been configured correctly on the right site of DNS-DIY reseller control panel.

To change your domains’ DNS, please go to your control panel of your current registrar.

Why is the DNS still showing the old one when I check it even if I have modified it with the registrar?

Our DNS check is based on the current data of the DNS root server. If you modify DNS with the registrar, it will take about 12-72 hours to be reflected on the root server.

Why can’t I receive emails when the resolving has taken effect?

  1. Please check whether your MX record is setup correctly;
  2. Please check to see if your mail server is setup correctly.

You may try our mail forwarding service if you don’t own an email server.

Why hasn’t the MX record taken effect?

Most of SMTP requires MX record to be pointed to a hostname instead of IP address.

For example, if you would like to setup as the mail server of whatis.cn, you can configure in this way,

  1. Resolve mail.whatis.cn to (please fill in mail for host column, and choose A for type column, then fill in for data column, click ‘Add’ button).
  2. Please configure the MX record of whatis.cn as mail (leave host column, choose MX for type column, fill in mail for data column and then click ‘Add’ button.)
  3. Configurate your email server at to accept emails for @whatis.cn.

If you fill in mail for host column in the second step, then all the emails sent to @mail.whatis.cn (not @whatis.cn) will be received by This may not meet with your original intention.

Why are there some hostnames ending with ‘.’ (a dot), while some not? What’s the difference?

A host name ending with a dot means FQDN(Full Quality Domain Name); While that without a dot refers to the host name under the appropriate domain.

For example,

  1. Add a CNAME record "abc" which pointed to "123" under whatis.cn, then abc.whatis.cn means resolving using 123.whatis.cn.
  2. Add a CNAME record "abc" which pointed to "candidinfo.com", then abc.whatis.cn means resolving using candidinfo.com.

Why is priority always setting as ‘0’?

The priority value is only effective on MX record. For other types of records, the value will be disregarded.

Can I setup wildcard DNS records to my domain names?

Yes. Please fill ‘*’ for hostname.

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