RT-AC86U. Port scan shows port 21 open to WAN. FTP has always been off. How do I close it?

[markpaterson]

I'm running Merlin 384.13 on an ASUS RT-AC86U. I installed Merlin yesterday for the first time and did a factory reset after installing.

I've just done a port scan of my home's external IP from a computer outside of my home network and it revealed that Port 21 is open. I have never used the FTP setting on the router, and I confirmed that it's off and the "allow FTP over WAN" is off too.

How do I close this port? I see nothing in the entire firmware that even mentions port 21.

Thanks

 

[ColinTaylor]

Is it actually open or is it detecting your ISP's equipment and thereby creating a false positive? Try connecting to it from outside your network and see what the banner message says.

That said, there was this fix for FTP in 384.13:

384.13 (31-July-2019)
  - FIXED: FTP would be accessible from the WAN even while disabled
           if you had DualWAN load balancing enabled, or IPTV
           configured.

 

[eastavin]

I've just done a port scan of my home's external IP from a computer outside of my home network and it revealed that Port 21 is open.

Thanks

Try another scan with Gibson shields up for comparision https://www.grc.com/x/ne.dll?bh0bkyd2