there is any way to find that which switch port connected to mgmt port of fortigate? for example can i enable lldp on Cisco switch and Fortigate together? Fortigate 1500D (version 5.6.2) and switch is cisco-2960x-24TSL(ios ver 12.2)
You can check the MAC address table on the switch to see on what port you learned the MAC address of the Fortigate's management interface.
It should be possible to enable LLDP on the Fortinet as of FortiOS 5.2 as well according to their documentation:
config system interface edit <name> set lldp-transmission enable end end
You can enable LLDP on your switch using the command
lldp run. After that, you can use
show lldp neighbors to see which LLDP speaking hosts are seen.