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I have my forward zone configured and now I am writing my reverse zone configuration. I've read through Pro DNS and BIND book and the examples given are if you own a portion of an IP address space a.b.c.0/24. However, I'm hosted through a third party and the IP's assigned are completely random and in different subnets. Would this require me to have a single zone file for each host/IP then? I'd also assume that if two hosts happen to fall in the same /24 network, I couldn't use zone "c.b.a.in-addr.arpa" { either as I don't own all hosts in the /24 network?

ie

 zone "d.c.b.a.in-addr.arpa" {
     IN PTR example.com
 }

 zone "z.y.x.v.in-addr.arpa" {
      IN PTR mail.example.com
 }
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You would need to talk to the owner(s) of those reverse zones and convince them to add suitable reverse record(s) to their zone file. An email address might be obtained from a SOA lookup on the zone (it's the field just before the serial, with the email @ replaced with a .), though going through the usual contact channels for your network provider (ISP, virt colo hoster, etc.) might be a better approach these days.

$ host -t SOA 10.in-addr.arpa
10.in-addr.arpa has SOA record prisoner.iana.org. hostmaster.root-servers.org. 1 604800 60 604800 604800

Real, actual zones can be hit or miss, and might be complicated by CIDR zones, hence the recommendation that you contact the admins via their published support channels:

$ host microsoft.com
microsoft.com has address 134.170.185.46
microsoft.com has address 134.170.188.221
microsoft.com mail is handled by 10 microsoft com.mail.protection.outlook.com.
$ host -t SOA 185.170.134.in-addr.arpa
185.170.134.in-addr.arpa has no SOA record
$ host -t SOA 170.134.in-addr.arpa
170.134.in-addr.arpa has SOA record ns1.msft.net. msnhst.microsoft.com. 2015090302 7200 900 7200000 3600
$ 
  • So stick with forward zones and have the host provide reverse? I believe I read the FAQs that they can do this. – debuser14 Sep 3 '15 at 19:10
  • Yup. Honestly, reverse records are somewhat less used these days... – thrig Sep 3 '15 at 19:37
  • @debuser14: Unsure what are you speaking about. Can you set up reverse zones in your SOHO network? Yes. Can you set up a reverse zone valid in the Internet? Unlikely. – Incnis Mrsi Sep 12 '15 at 17:11

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