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N_W
Explorer
March 21, 2025
Question

Issue with PTR Records Deletion After DHCP Lease Expiry on FortiGate 7.2.10

  • March 21, 2025
  • 7 replies
  • 3840 views

Hello, I am using FortiGate version 7.2.10. I am distributing DHCP via the FortiGate interface over VLAN. The lease time is set to 7 days, but when the lease expires, PTR records on the DNS are deleted. There are DNS-update commands available in the DHCP server CLI, but it seems like those commands are not working, as it doesn't allow me to run them. How can I dynamically resolve this issue and make it permanent so that PTR records are not deleted? Best regards.

7 replies

AEK
SuperUser
SuperUser
March 21, 2025

Hi B_B

Can you explain which PTR is deleted, on which DNS server and give a screenshot if possible?

AEK
N_W
N_WAuthor
Explorer
March 21, 2025

Hello, in Active Directory, it is being deleted from PTR. Actually, the issue I'm experiencing is mentioned in the link https://community.fortinet.com/t5/Support-Forum/Does-Forti-actually-update-DNS-from-DHCP/td-p/9607, and it even says that I won't be able to fix this issue in previous versions. However, is this issue present in this version?

N_W
N_WAuthor
Explorer
March 21, 2025

sssptr.jpg

AEK
SuperUser
SuperUser
March 21, 2025

Does it resolve the issue if you configure a DHCP relay on FG interface to forward to your AD?

AEK
N_W
N_WAuthor
Explorer
March 24, 2025

Hi, thank you for your interest. However, I think I was misunderstood. I don't want to use relay, I want to create a DHCP pool on the FW interface. I have already done that, but my actual problem is this: when I create a DHCP pool on the FW interface, I am facing the issue where the PTR (reverse DNS) records of the IP addresses coming from that block are missing on the DNS.

AEK
SuperUser
SuperUser
March 24, 2025

I understand the issue but I don't know a solution that can be implemented on FG side. However I actually I always see companies using AD DHCP server (instead of FG's) for the corporate clients, and I know they don't have such issue when they do so.

AEK
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