Set the same VLAN on two aggregated interfaces

[3d1l]

Hello,

Using Fortigate 100D with 5.6.5

I need to pass the same VLAN on two aggregated interfaces. None of my switches are big enough to be considered a "core" switch. So I want to use the fortigate as a "core switch". I'm going to connect the switches using aggregated interfaces. Each aggregated interface on the switches and on the Fortigate will be compose of two physical ports. It will be a star topolgy.

I created a VDOM in flow and transparent mode, then I defined a software switch (also tried a hardware switch). Then I proceeded to create the aggregated interfaces but the ports that are already members of the software switch are not listed neither available to be selected to create the aggregated interface. Then I removed the ports from the software switch and created two aggregated interfaces, but then I can not set the same VLAN on both interfaces, then I created the VLAN interface but again I can not select the aggregated interface to be assigned to the VLAN.

Please advice.

 

[ede_pfau]

The only other missing combination is to have 2 LACP trunks and trying to form a software switch out of those.

Never tried that, and I doubt if would work.

Given a FortiSwitch is dirt cheap (FS-124E or FS-108E) and supporting LACP and more stuff, I'd rather go that way than mutilating my FGT. YMMV.

[3d1l]

Yep tried that already. Once the ports are assigned to the LACP interface, they are not listed to be selected for the software/hardware switch.