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مشاهدة النسخة كاملة : ما هو What is PTR Record / Reverse DNS entry (rDNS)



Rise Company
05-10-2021, 07:10
ما هو What is PTR Record / Reverse DNS entry (rDNS)
Reverse DNS (PTR) has to be set by your ISP, not you. Their DNS server is what is queried as they own the IP address, not yours.
Configure reverse DNS properly for mail - How to set up reverse DNS - Why setting reverse DNS for your email?

https://www.rise.company/upload/uploads/163341047969671.png

المشكلة :

عند التحقق من rDNS يكون غير صحيح يجب ان يكون مطابق مع اسم السيرفر حتى يصل الى Inbox
وتجنب مشاكل السبام الشائعة وحدوث blacklist للاى بي الخاص بالسيرفر.

حل المشكلة :

يجب ان تتواصل مع مقدم الاى بى الخاص بالسيرفر لكى يقوم بتنفيذ ذلك
حيث لا يمكنك من خلالك ولكن مقدم الاى بى هيفعل ذلك وهيسئل عن الاسم المطلوب ptr record
وهيطلب بيانات الدخول على السيرفر لضبط الاعدادات به.

* ناكد لا يمكن ان تدخل record بنفسك لابد من مقدم الخدمة لانه له صلاحية Dns root

حل اخرى قد تفيد فى بعض الاوقات ولكن لن يحل المشكلة
https://support.cpanel.net/hc/en-us/articles/4405084705559-How-to-enable-custom-mail-HELOs



Reverse DNS (PTR) has to be set by your ISP, not you. Their DNS server is what is queried as they own the IP address, not yours.

A PTR (pointer) record maps an IP address to the domain name. It’s often called a "reverse DNS entry" because it converts an IP address to a name.

PTR records are mostly used as a security and anti-spam measure, to verify that a mail server address is allowed to send an email to a particular hostname. The reverse DNS entry checks if a server name is indeed associated with an IP address from where the connection was initiated.

In order to set up a reverse DNS entry that will connect an IP address to your domain (e.g., 127.0.0.1 should be mapped to yourdomain.com), you will need to contact your IP address provider to create a PTR record for the IP address.

Please keep in mind that PTR records are supported on our VPS and dedicated servers only. Still, it is also possible to create the PTR record on Shared and Reseller packages if you have a dedicated IP address. For that, reach out to us via Live Chat so that we can set the required PTR record.

Why setting reverse DNS for your email?

Setting reverse DNS means that you will have all of the domain names for all IPs you have, which means that it could work as spam filter by making sure that the IP used is really corresponding to this domain name and it’s not a fake one.

Let me explain this in a simpler way if someone is trying to send you an email from [email protected]. Before delivering this email to your email server, the reverse DNS could retrieve the IP address of the sender while he made his first handshake. Using this IP address and the sender domain name the rDNS could make sure of the sender identity in order to allow message delivery or deny it or mark it as spam.


How to configure the reverse DNS?

Configuring reverse DNS require to enter a PTR record over the DNS server.

What is PTR record?

It is a Pointer Record that resolves an IP address to a qualified domain name.
It consists of the IP address entered in a reverse way followed by “in-addr.arpa” where in-addr.arpa is where the PTR record is stored over DNS.
The one responsible to manage this PTR is the internet service provider (ISP) which is the entity that owns your IP address and some other IPs in your zone, so you should contact your ISP so they could delegate the reverse DNS for your IP zone.
If you are the one responsible then you should first create a reverse DNS zone by dropping the last digit of your IP address, reverse it and then follow it by “in-addr.arpa”
for example, if your IP address is: 197.133.44.128, then your DNS zone will be 44.133.197.in-addr.arpa.
after creating your zone file, now you can create your PTR record with it right format, for our example, it will be: 128.44.133.197.in-addr.arpa, et voilà you have created the Reverse DNS.


المرجع:
https://www.namecheap.com/support/knowledgebase/article.aspx/10057/10/what-is-ptr-record
https://www.godaddy.com/help/set-up-reverse-dns-for-my-gen-4-dedicated-server-32189 (https://www.namecheap.com/support/knowledgebase/article.aspx/10057/10/what-is-ptr-record)
https://community.spiceworks.com/topic/1648187-configure-reverse-dns-properly-for-mail
https://support.cpanel.net/hc/en-us/articles/4405084705559-How-to-enable-custom-mail-HELOs