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Questions tagged [reverse-dns]

Reverse DNS lookup is the determination of a domain name that is associated with a given IP address using the Domain Name System (DNS) of the Internet.

Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address using the Domain Name System (DNS) of the Internet.

Computer networks use the Domain Name System to determine the IP address associated with a domain name. This process is also known as forward DNS resolution. Reverse DNS lookup is the inverse process, the resolution of an IP address to its designated domain name.

Source: Wikipedia.

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How to setup PTR (Reverse DNS) at Godaddy DNS manager

My hosting provider already did PTR setup. Now i have to setup it at my DNS holder i guess. What am i supposed to do at my Godaddy account. thank you. my ip : 64.250.113.235 and you can check my ptr record from…
Furkan Gözükara
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What is reverse DNS?

I've lot of *.in-addr.arpa domains requests in my OpenDNS account. I know this should be normal and it's about reverse DNS. I've been reading here and there but still I can't really get how it works and why I get so much requests (higher number than…
Pitto
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Apache httpd won't stop doing reverse DNS requests for clients' IPs

Obviously my Apache httpd instance is doing reverse DNS (RDNS, give me the hostname for this IP address) lookups for each incoming client connection's IP address. This is bad. Especially since sometimes resolution fails with a missing PTR record -…
Paul
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Remote connection to MySQL server takes very long

I have a MySQL 5.0.75 server running on my Linux notebook to which I want to connect from another machine in the local network. This connection takes 5-6 seconds: mysql -h 172.22.65.101 -u myuser -p123 A ping to the MySQL host: PING 172.22.65.101…
Lennart
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Is it bad to have the reverse DNS for two IPs point to the same domain name?

I am in the process of setting up a new server for my web application (the site will be moved, it is not for load balancing or the like), which has a different IP address from my existing server. My current server has a reverse DNS PTR record set up…
Daniel Vandersluis
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How important are PTR records for Email Servers?

Does anyone know of any studies done to show how much email will be rejected if there is not ptr record for the SMTP banner name of an email server? Are reverse checks always done when enabled, or is it sometimes configured so if an spam program…
Kyle Brandt
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Reverse DNS Setup for an IP with multiple domains

I am trying to clarify my Reverse DNS PTR lookup for a domain. I have a server with a single IP addresses and multiple accounts, all sharing that IP address; My PTR is currently: 24.210.31.in-addr.arpa. 14400 IN PTR domainname.co.uk. But the…
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How does a Reverse DNS lookup work with regards to spam filters?

I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process. I want to make sure my emails will pass this check. How exactly can…
codeflunky
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How do I perform a LLMNR query?

I wish to perform a LLMNR query explicitly. My current environment includes DNS servers so the ping (ping -a specifically) is doing DNS queries to resolve the name. I can disable my DNS in my network configuration, but that isn't an ideal…
DarkSheep
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sshd tries reverse DNS lookups with UseDNS no

sshd seems to almost always try to perform a reverse DNS lookup on new connections. For hosts without a PTR entry this causes delays of 5 seconds per query. Sometimes it accepts the connection immediately, sometimes it tries to resolve once,…
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Best Practice: notify email sender that their reverse lookup is broken

This probably should be a wiki, not entirely sure. Before I begin, the external server that performs scanning is a custom amavis/postfix/fortigate pipeline; it is suggested that any changes work within that environment. I have enabled reverse…
Avery Payne
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How do I change reverse DNS on Google Cloud Compute?

How do I change reverse DNS on Google Cloud Compute? I want to add reverse DNS to Google Cloud Compute and can't figure out howto do it. I want to map 11.97.196.104.bc.googleusercontent.com to ns1.example.com…
Surjit Sidhu
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Is it valid to have several IP addresses resolving back (PTR) to one name that doesn't match either of the relevant A records?

I have several devices, each with its own IP address. There are various names pointing to these addresses (in several different domains). As an example the device with IP address 10.0.0.1 is known as dev1.example.com and abc.example.net IP address…
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Reverse DNS is not a valid Hostname error from MXToolBox

I can't send email messages from my server. However, I can receive email messages. I set up my server the exact same way I did many times which I've proven it works and it's pretty straightforward and consist of: Create a DigitalOcean Droplet…
Jason Lint
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How to determine which DNS server has the authority to set rDNS (PTR records)?

or to re-phrase... How to determine to whom authority has been delegated to set rDNS? Background In a multi-tier environment, where a block of IP's is assigned, then further split and assigned (process repeats a few more times), how can one…
Peter White
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