I am attempting to set up VSFTPD on a new server running CentOS 7. This server was set up with most common programs not installed, and I've been trying to muddle my way through. I've got an older server, running an older version of CentOS (and presumably an older version of VSFTPD) that I was attempting to use as a model. I am using the same ftp username/password for both systems.

I can get into the FTP directory on the original server either through the Windows command line, or through the program my predecessor built in Delphi 7 (using the Indy FTP components). With the new machine, I can connect from the Windows command line, but not with the external program. With the external program, during the 'connect' call to the third-party component, I'm instead getting an error message 'Socket Error # 10060 Connection timed out'. I am receiving this error both with the configuration file from the fresh VSFTPD install on the new system, and with the copied configuration file from the old system.

Given that both connections work on the old system, I'm assuming I've somehow done something wrong while configuring the new one.

Could someone please give me a good starting point for where in the configuration files I need to be looking, or if not the configuration files, where else I might be having problems?

Verify you've opened both ports 20 and 21 in firewalld (new frontend for iptables - don't edit iptables directly).

However, if this is a new server it might a be a good time to push abandoning ftp in favor of sftp which is much more secure. I was able to push back when we moved to a new server a few years back to eliminate all the ftp accounts. These days most of the B2B partners we deal with are shutting down ftp and making us use sftp to reach them.

Windows users can access sftp using WinSCP on their workstations which is a free download. (WinSCP by the way can also be used to connect to ftp servers.)

Thank you for the advice - it looks like I didn't have port 20 opened. However, after adding that and restarting firewalld, I'm still seeing the same results from the Delphi program afterwards - it blocks for a time on the connect call, then errors out with the same '10060' error.

Given this, what is the likeliest next thing I should be looking for?

Have you compared /etc/vsftpd config files from your old server to those on your new server?

Have you verified vsftpd is in fact running on the new one:
systemctl status vsftpd

Have you verified whether anything is listening on port 21:
lsof -i :21