Selfhosted @lemmy.world drkt @feddit.dk 1 yr. ago

rDNS, how?

I'm on at least 2 blocklists at this point for the crime of not having reverse DNS set up. I don't know how rDNS works. No amount of reading Wikipedia is helping me understand what I have to do.

I have a domain at a registrar which gives me bog standard DNS.
I have Apache running on my network.
I have PiHole running on my network.

My understanding is that rDNS is not set up at my registrar, but somewhere in my network. What do I do?

Thank you for your time.

47 comments

rDNS is something that is not set up by your domain registrar. It's set up by your ISP or cloud VM provider.
This is usually done by owner of the IP address block. If this is for a VPS or similar it will be your hosting provider. If you get a static IP from your internet service provider you will have to speak to them. Although depending on the policy of the provider this may be a business option only.
- You are right, more specifically in case anyone is curious it usually has to be whomever owns the public IP addresses because that is who would own the reverse zone for that IP block according to the internet root dns servers in most circumstances. In OPs case you are probably right, this is probably the VPS provider but not always.
- Thank you so much. Luckily my ISP has been nice so far, I guess we'll see.
Are you actually trying to send mail from your own smtp server? You mention apache and pihole which are completely unrelated.
- No emails just routing issues.
  
  Copy pasted but I have routing issues that neither my ISP nor the people who suffer from it can pinpoint. I’m so far down this rabbit hole that I’m assuming my IP got on a blacklist that’s sitting on some random networking infrastructure and I’m just trying to resolve all blacklist issues on the off chance that it works.
  
  rDNS won't really help with that, it's just a DNS lookup that ties your IP to a hostname, typically used for mail server spam controls.
Can you expand on how you got blocked? First time I’ve heard of this.
- I would love to tell you why they do this, but I can't. I can only tell you that they tell me it's because I don't have rDNS
  
  These guys are blocking me http://www.uceprotect.net/en/rblcheck.php "Level 1 HIGH DNS problem WARNING: No Reverse-DNS (PTR) is assigned to your IP"
  
  These guys are blocking a friend of mine who has the same setup as me https://matrix.spfbl.net " No rDNS was found. This IP has been flagged because have none valid FCrDNS. Register a valid rDNS for this IP, which points to the same IP. The rDNS must be registered under your own domain for you be able to delist it."
  
  Are you sending email from your ip?
  
  If not this is irrelevant. Those block lists are only for email related spam filtering.
  
  If you are, don't send email from a home isp
  
  Ugh, uceprotect is the worst of the worst with overly strict rules to encourage paying them to whitelist your IP. Just ignore them.
  
  Depending on your isp, you may be required to have a business class plan with a static ip. I went through something similar years ago for my business. This is old documentation for Verizon, but it's a hint.
  
  https://community.verizon.com/t5/Fios-Internet-and-High-Speed/How-to-make-reverse-DNS-point-to-my-own-domain/td-p/1376002

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

Fewer Letters	More Letters
DNS	Domain Name Service/System
IP	Internet Protocol
NAT	Network Address Translation
SSL	Secure Sockets Layer, for transparent encryption
TCP	Transmission Control Protocol, most often over IP
VPN	Virtual Private Network
VPS	Virtual Private Server (opposed to shared hosting)

7 acronyms in this thread; the most compressed thread commented on today has 11 acronyms.

[Thread #72 for this sub, first seen 21st Aug 2023, 20:45] [FAQ] [Full list] [Contact] [Source code]

What are you trying to do OP?

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