Ftp – vsftpd : limit connection to a set of IP addresses

Either pasv_address needs to be the external IP address, or pasv_addr_resolve=YES needs to be set so that the hostname you entered will be resolved when vsftpd starts. If you use a hostname with pasv_addr_resolve, vsftpd has to be restarted if the IP address changes.

I was having trouble with this issue for the past few days, at first I followed the route of the one answer of installing proftpd. That did not pan out as I'd hoped so I tried pure-ftpd, failing that I reverted back to vsftpd, what solved the issue for me was increasing the amount of passive ports, I had previously only allowed the range 10090:10100, which is only 10 ports.

I've since allowed a greater range of ports for vsftpd and it has solved my issue, I no longer get that error when uploading long lists of files with 10 files at a time.

Hope it helps anyone who runs into this issue next time.