Set reverse DNS to ip address instead of hostname (ie, remove hostname *.ip.linodeusercontent.com)
I would like to set the reverse DNS on my Linode server to its IP address instead of hostname.
When I go to https://cloud.linode.com/linodes/[id-redacted]/networking there is the option to "Edit RDNS". However, when I am not allowed to set the value to the server's IP address and setting the value to blank defaults back to the original hostname: [unique-ip-address].ip.linodeusercontent.com.
Older articles on the subject such as this one https://www.linode.com/community/questions/18466/remove-reverse-dns-settings appear to be either incorrect or outdated.
This is easily to accomplish with other cloud services such as Vultr. I would like to stay with Linode, please advise.
Thank you!
2 Replies
Is there an Akamai forum I should be asking instead?
hdiep
Linode Staff
The reason why you're unable to set your rDNS value to point to an IP address is because it's not possible. With how rDNS works, it's responsible for resolving an IP address to a hostname. Whereas the A record maps the domain name to an IP address. rDNS and forward DNS work together to create a consistent reference between IP addresses and DNS records on a domain. IP points to domain via PTR record, domain points to IP via A record. In case you were interested in learning more, I've provided a few guides below that go over how DNS works:
- Overview of DNS and DNS Records | Linode Docs
- How To Configure rDNS (Reverse DNS) on a Compute Instance | Linode Docs
- A and AAAA Records | Linode Docs
I haven't used Vultr before and can't confirm if that's possible on their end, but I came across a screenshot of how they've configured their default rDNS value. With their setup, it seems similar to our naming convention:
- Linode's: [unique-ip-address].ip.linodeusercontent.com.
- Vultr's: [unique-ip-address].vultr.com.
In the other community post that you've shared, if you've tried following the steps below that were referenced:
From the "Networking" tab, click the 3 dots to the right of your server's IP address and select "Edit RDNS".
From the tab that opens, make sure that the box entry is empty and select "Save".
You'll be met with [unique-ip-address].ip.linodeusercontent.com. because that's the intended rDNS value. Otherwise, you could set that value to point to a domain name instead.