Why can't DNS create multiple A records with different names using the same IP?

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The following was translated by DeepL

Example: There is an IP which is both a www server (www.xyz.cn) and an ftp server (ftp.xyz.cn).

Question 1.

Why can't DNS create multiple A records with different names for the same IP? Instead, it needs to use CNAME to create them? As in the following two images.图片1


Question 2.

After creating an ftp with CNAME, when I need to reverse query, how can I query the ftp domain name of

Thanks for your help!

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  1. Dave Patrick 426.2K Reputation points MVP

    You can't. A CName is an alias. When you do a DNS look up on a CName, you get back the hostname, not an ip address. You'll need to do 2 lookups to get the ip address. CName -> MachineName -> ip address. A single A record "MachineName" can have MULTIPLE CNames that point to it.

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