issue sending backup to ftp server

[birillo]

Hi,

I'm trying to schedule a full-config backup, from a 40F to a ftp server visible on vpn s2s.

using this command:

execute backup full-config ftp '/xxx/FGT_%%date%%.txt' 10.3.64.113 user pwd

I receive this output:

"Send config file to ftp server via vdom root failed."

ping from fgt to the server not working, so I did a packet capture for destination ip 10.3.64.113 and I found that the Fortigate use, by default, the wan interface, but in this case that port is disabled and I'm using A port as a Wan port.

what can i do to route the backup procedure correctly via vpn s2s using the correct tunnel-interface?