Issue
If you configure more than 256 Firebox interfaces (external, trusted, optional, or custom interfaces) to use DHCP relay, DHCP relay may not work on some of these interfaces.
For example, if the Firebox has 256 or fewer interfaces, 100 of which are configured for DHCP relay, DHCP relay works on all 100 interfaces. If the Firebox has more than 256 interfaces, 100 of which are configured for DHCP relay, DHCP relay might not work on all 100 interfaces.
Workaround/Solution
We recommend that you upgrade to Fireware v12.6.3 / v12.5.6 or higher.
Fireware v12.7 or higher — DHCP relay works on all interfaces configured for DHCP relay if you configure 750 or fewer interfaces to use DHCP relay.Fireware v12.6.3 / v12.5.6 — DHCP relay works on all interfaces configured for DHCP relay if the Firebox configuration includes 750 or fewer interfaces (external, trusted, optional, or custom interfaces), regardless of whether you configure interfaces for DHCP relay. For example, if the Firebox has 750 or fewer interfaces, 100 of which you configured for DHCP relay, DHCP relay works on all 100 interfaces. If the Firebox has more than 750 interfaces, 100 of which you configured for DHCP relay, DHCP relay might not work on all 100 interfaces.
If you do not want to upgrade Fireware, you can add a local DHCP server on interfaces where DHCP relay fails or consider using the DHCP server on the Firebox to handle DHCP for those interfaces.
