DHCP issue on fortiOS 7.4.7

[akcybteam]

Hello,

we are currently running our Fortigates on FortiOS 7.0.13 and want to upgrade them as the version is coming out of support in next few months.

we first considered 7.2.10 (7.2.11 now) but Fortinet recently changed their recommanded version to 7.4.7 for our models.

Reviewing the release notes, I noticed this known issue : 

1069208

If the DHCP offer contains padding when DHCP relay is used, the DHCP relay deletes the padding before relaying the packet.

From what I understand on various internet sources, removing padding from DHCP packets could be an issue for certain devices that could no more get an IP. I found nothing specific for Fortigate setup however.

This is a major issue for us as our main Fortigate is used as a DHCP relay, and it is the only one so we cannot test it before.

I was curious if someone encountered DHCP issues on 7.4.7 ?

[ebilcari · Accepted solution]

This issue was originally reported and affects only certain older modem/routers that had problems accepting DHCP offer packets smaller than 300 bytes. Technically it should not affect other devices. This behavior is changed and the change will be included in 7.4.8.

[akcybteam]

Thanks for the quick reply ! we will look into such devices and wait for 7.4.8 if applicable.