I am trying to upload a file fom my RB2011 to my Synology NAS

/interface bridge> /tool fetch address=192.168.0.10 upload=yes src-path=current_config.rsc user=admin password=password dst-path=/tmp/c.rsc mode=ftp
failure: cannot open FTP socket

A packet capture on the synology shows no attempts of any traffic outgoing.

I set up an output chain to log everything but the common traffic (to avoid chattiness)

[admin@gw] /interface bridge> /ip firewall filter print chain=output
Flags: X - disabled, I - invalid, D - dynamic
0 chain=output action=accept protocol=tcp port=22,8291,80 log=no log-prefix=""

1 chain=output action=accept log=yes log-prefix="OUTPUT"


But even that doesn't show anything

Is there any way to further debug this?