I would suggest sk97642 Troubleshooting DHCP Relay Issues for help. A short step-by-step guide to check/configure DHCP relay on R77 and up:
1. Each BOOTP primary address should be the VIP of the interface and point to the DHCP server(s)
2. On the DHCP server(s) should be a route back to the served network
3. Kernel parameter fwx_dhcp_relay_nat should be set to 1 on both cluster members (checked)
4. On management machine, in the file "table.def" of the RELEVANT GATEWAY VERSION - search the parameters "no_fold_services_ports” and “no_hide_services_ports” and make sure <67,17> and <68,17> do not exist in those lines (delete them).
5. Disconnect all GUI clients from management, then through GuiDBedit search under "network objects" for “perform_cluster” and make sure the parameters “perform_cluster_fold” and “perform_cluster_hide_fold” are set to “true”
6. Install policy
7. Perform the following procedure to add a new NAT rule above the NO NAT rule for the internal networks:
Create new/check objects with the following IP addresses:
Group with both DHCP servers
VIP of the relayed network
Internal network to be relayed
Then add a new manual NAT rule of the following:
Original packet:
Source: Relayed Network
Destination: DHCP servers
Port: bootp(67)
Translated packet:
Source: VIP of relayed network
Destination: Original
Port: Original
CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist