Troubleshooting Tip: FortiSwitch firmware upgrade stuck at 0% from FortiGate GUI

When trying to upgrade FortiSwitch firmware under Wifi & Switch Controller -> Managed FortiSwitches, it stuck at 0% without any errors. 


Checking connectivity between FortiGate and FortiSwitch using SSH and getting 'No route to host' error:

Demon # exec ssh admin@192.168.16.5
ssh: connect to host 192.168.16.5 port 22: No route to host

This indicates a connectivity issue between FortiGate and FortiSwitch. Check the following items to make sure the connection is good:

1. Checking routing-table using the command 'get router info routing-table database' to make sure the connected route is via the FortiLink interface.
   
   

Demon # get router info routing-table details 192.168.16.5

Routing table for VRF=0
Routing entry for 192.168.16.0/28
Known via "connected", distance 0, metric 0, best
* is directly connected, fortilink

2. Checking the ARP table using the command 'get sys arp'.

Demon # get system arp
Address Age(min) Hardware Addr Interface
192.168.16.5 0 80:80:2c:ac:45:74 fortilink