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

[B_B]

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.

[AEK]

Hi B_B

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

[B_B]

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?

[B_B]

sss

[AEK]

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

[B_B]

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]

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.

[B_B]

I understand. In the Fortigate architecture, opening DHCP pools on VLANs on the interface is actually not a recommended setup. They should create this scope on the DHCP server instead. Do you have any resources regarding this, such as a Fortinet document?