DNS 設定-A CNAME MX NS 說明

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DNS 設定，A CNAME MX NS AAAA PTR 說明
DNS資源紀錄(Resource Record)介紹

DNS server內的每一個網域名稱都有自己的檔案，這個檔案一般會稱為區域檔案 (zone file) ，

例如”named.ca”或”named.local” 檔案…等等。

區域檔案是由多個記錄組成的，每一個記錄稱為資源記錄(Resource Record，簡稱RR) 。

在設定DNS名稱解析、反向解析及其他的管理目的時，您需要使用不同類型的RR(資源紀錄Resource Record)，底下將介紹常用的RR類型及表示法。


NS
name server，用來指定操作的DNS伺服器主機名稱，需注意的是不可以IP位址表示。

A NS record, sometimes called a glue record, allows you to delegate authority for a hostname to another name server. You need to know the hostname of the name server you wish to delegate authority to.
例：
IN NS dns.bonny.com.tw.

A
address，將DNS網域名稱對應到IPv4的32位元位址。

An A record can point a host name to an IP address. To point just 22ace.com to an IP address, leave the "Record Host" field blank. To point www.22ace.com to an IP address enter www into the "Record Host" field. To point all sub domains for 22ace.com that do not already have a host record to an IP address enter * into the "Record Host" field. You can add multiple host records for a domain name.

例：
server IN A 59.123.101.61


AAAA
可將DNS網域名稱對應到IPv6的128位元位址。

An IPV6 (AAAA) record can point a host name to an IPV6 IP address. To point just 22ace.com to an IP address, leave the "Record Host" field blank. To point www.22ace.com to an IP address enter www into the "Record Host" field. To point all sub domains for 22ace.com that do not already have a host record to an IP address enter * into the "Record Host" field. You can add multiple host records for a domain name.

例：
bonny.com.tw. 86400 IN AAAA 3ffe: :bbb:93:5


PTR
pointer，定義某個 IP 對應的 domain name，即將 IP 位址轉換成主機的FQDN。
例：
20 IN PTR mail.bonny.com.tw.


CNAME
canonical name，可為同一部主機設定許多別名，例如 mix.twnic.net.tw的別名可為 http://www.bonny.com.tw/和 ftp://ftp.bonny.com.tw/，因此所設定的別名都會連至同一部伺服器。

A CNAME or canonical name record points a hostname with no other records to another valid hostname. The canonical name you use should have no other DNS records associated with it. CNAME's should only be used in a very few instances, for common aliases and host names use an A record instead. If you do not understand what CNAME's are used for, then chances are you should not be using them. The misuse of CNAME records can cause problems with the resolution of your domain name if not used properly.
例：
www IN CNAME mix

MX
mail exchanger，設定區域中擔任郵件伺服器的主機，所有要送往那部機器的 mail 都要經過 mail exchanger 轉送。
而數字則是該主機郵件傳遞時的優先次序，數值越低表示有越高的郵件處理優先權。

MX records are used to deliver email associated with your domain name, such as info@yourdomain.com, to the appropriate mail server, for instance, mail.yourdomain.com.

Name.com Email Service Customers
If you have purchased email service and created email addresses through Name.com, a MX record has been automatically generated for your domain name, and you need do nothing more in order to route email associated with your domain name to our mail server. On the preceding web page, you should see a MX record with yourdomain.com listed as the Record Host and mx0.name.com denoted as the Record Answer.

Third-Party Email Service Customers
If you are using a third-party mail server, create a MX record (on this web page) in which you leave the Host name field blank and enter the name of your third-party mail server into the Mail server field.

Customers Who Provide Their Own Email Service
If you are using your own mail server, you must do the following. First, create a Host record with the name of your mail server, most often mail.yourdomain.com or smtp.yourdomain.com, in the Host name field and the Internet Protocol (IP) address of your mail server in, naturally, the IP address field. Second, make a MX record in which you leave the Host name field blank and enter the name of your mail server, again, mail.yourdomain.com or smtp.yourdomain.com, in the Mail server field.
例：
server IN MX 10 mail.bonny.com.tw.
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