Shane,   > If port 21 is open on the modem the it is likely that the modem has a device on the LAN with an FTP server running. None of my computers are running ftpd - it is something I have routinely turned off for decades . .    > If you prefer to set up port forwarding manually we advise to disable the uPnP.   Well that's interesting - when I go to look at the uPnP status, there IS in fact a service running that was unexpected but is in fact OK (ie it is NOT ftp) - however I will disable uPnP and manually add the auto opened port.  It will be interesting to see if disabling uPnP fixes the ftp problem . .    > Let us know should you require further assistance.   Thanks - I will update this thread after uPnP disabling . . ... View more

> When you ran nmap, was it on your computer on the home network? It would be looking at ports open on local side, like port 80 is open for router admin.   Yes, but I used nmap on the FQDN not the local IP . .    > Did nmap report any others? Like 139 and 445? I think these are used for accessing USB storage. VR1600 supports FTP (port 21), SMB (ports 139 and 445). These are open on my VR1600.   PORT STATE SERVICE 21/tcp open ftp 25/tcp open smtp 53/tcp open domain 80/tcp open http 88/tcp filtered kerberos-sec 443/tcp open https 587/tcp open submission 993/tcp open imaps 1900/tcp open upnp 2525/tcp filtered ms-v-worlds 5000/tcp filtered upnp 8200/tcp open trivnet1   > You can use sites like portchecktool.com to check if specific ports are open or not.   Result:  "Problem!  I could not see your service on xxx.xxx.xxx.xxx on port (21)."   Using: https://hackertarget.com/nmap-online-port-scanner/   I get:   PORT STATE SERVICE 21/tcp filtered ftp 22/tcp filtered ssh 23/tcp filtered telnet 80/tcp open http 110/tcp filtered pop3 143/tcp filtered imap 443/tcp open https 3389/tcp filtered ms-wbt-server - filtered being a little more reassuring . . Thanks, Phil.   ... View more