Is there a way to use SSH port forwarding from the WAN to get access to a USB drive on another LEDE machine which is on the LAN? The USB drive is already shared out on the local network, but I occasionally need access to it remotely. I'm not sure if SSH port forwards can work, maybe setup a basic FTP server and port forward 20 & 21? Or is there a better way?
If you already have network sharing setup then what you want is a VPN.
You could build the firmware for each device with nfs support, then set up the device with the USB drive as an nfs server, and mount nfs share on the nfs client device connected to the WAN
Just forward port 22.
If you can ssh into lede from WAN, you can also scp stuff from the drive.
Now that is exactly the kind of solution I was looking for. Something simple involving SSH. I did have to add the openssh-sftp-server package to make it work with my Bitvise client. See more info here:
https://wiki.openwrt.org/doc/howto/sftp.server
Thanks everyone. Especially @Qualcomm