DHCP Helper on Standalone FortiSwitch

[zbrvenik]

We currently purchased some FortiSwitch 124F-FPOE switches for a client and are running into some odd issues getting the DHCP Helper feature to work properly.

DHCP Server exists at a central office with a bunch of branches connected to it via MPLS. So a hub and spoke topology, where all traffic from the branch sites is funneled back to the main office.

For whatever reason when we are using a FortiSwitch at one of these branch locations, the DHCP Helper function doesn't work properly on VLANs. The native vlan on the internal interface will forward the DHCP traffic, but the other DHCP Helper on VLAN10 will not forward DHCP traffic correctly.

I have confirmed routing is working properly because I can statically assign a device on VLAN10 and ping the DHCP server with no issue. There is nothing that would block this traffic.

Currently have a case open with TAC and they aren't able to resolve the issue either, wondering if anyone else has run into this issue?

I've tried running various different versions of FortiSwitchOS (7.2.x, 7.4.x, 7.6.x), and I get the same behavior from all of them.

[Anthony_E]

Hello,

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Thanks,

[Anthony_E]

Hello,

We are still looking for someone to help you.

We will come back to you ASAP.

Regards,

[Anthony_E]

Hi,

To configure DHCP helper on a standalone FortiSwitch:

1. Access the FortiSwitch CLI or GUI interface.
2. Enable DHCP relay or helper functionality.
3. Specify the IP address of the DHCP server to which DHCP requests will be forwarded.
4. Configure the VLAN settings if the DHCP relay is enabled per VLAN.
5. Verify the DHCP relay settings and ensure they match the network requirements.

Hope it will help.

Regards,