If it is layer3 switch and fortigate firewall and switch is connected on L3 interface means . Use "sh ip interfàce brief command
This command will display all interface status on switch . You will have visibility of IP subnet of interface connected to fortigate firewall
In case if firewall is connected with L2 switch then " show mac -address&...
With the 6000 chassis models, you can use https://IP:44320 To access the slave cluster members GUI. The last digit 0 is for the MDB master board (2220 for SSH, 2230 telnet, 16120 SNMP).
You can access the FPC's (1-6 last digit on the 6k models)
You could try https://IP:44320 (44330, 44340, etc, if you have more cluster members. The cluster member is the ...
Instead of creating 8 saparate internal networks for 8 saparate interface .There is a feasible to create sub -interface for all the internal networks . To overcome bandwidth utilization on subinterface Configured link . Use 3 interface and aggregate the links
Further down stream switch Connecting firewall with trunk port allowing all Vlans .