maybe the easiest way would be to create a switch on the FGT that has Port 1 and 2 as members.
Then only the swithch itself has to have an ip in that subnet.
Traffic between the cisco switch will then remain subnet internal and traffic that goes outside the subnet will need some policy (and maybe routing) on the FGT.
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"It is a mistake to think you can solve any major problems just with potatoes." - Douglas Adams
