FTP no longer works (KPN modem update)

After a recent update to the KPN modem, port 21 (FTP) may be blocked automatically. This means no connection can be made to FTP servers to upload or download files.

This is easy to fix by setting the firewall settings of the KPN modem to 'low'. This is the solution KPN itself offers.

If you still cannot get it to work, it is best to contact KPN support. Below you will find some relevant forum topics on this subject: