I just got a new ASUS router and am having trouble with the FTP service on my Qnap NAS, that had previously been working great on the old router.
I can connect to the FTP on the internet-facing IP just fine, and retrieve directory listings, but I can't download or upload a file due to connection timeout.
I connect to it on the internal IP just fine and transfer files up and down with no problem. Because of this, I'm assuming it's some setting in my router?
I have port forwarding set up for the FTP on port 20 and 21, and range 55536,56559 for passive connections.
Has anyone else had this issue, or is there something else I'm not doing in my router configuration that I should be? Thanks.