FTP reply code 220 is the first response sent by an FTP server after a client establishes a TCP connection on port 21. It is the server's greeting banner, indicating it is ready to accept commands. The banner typically includes the server software name, version, and sometimes the server hostname or a welcome message. After receiving 220, the client should send USER to begin authentication. If you never receive 220, the server is not running, port 21 is firewalled, or you connected to a non-FTP service. Some servers send a multi-line 220 response with a banner message, legal notices, or usage policies.
This is the expected first response when connecting to an FTP server on port 21. Every RFC 959-compliant FTP server sends 220 immediately after accepting the TCP connection. The banner text varies by server software (vsftpd, ProFTPD, Pure-FTPd, FileZilla Server, IIS FTP).
When connecting to an explicit FTPS server (port 21 with AUTH TLS), the server first sends 220, then the client sends AUTH TLS to upgrade to encryption. For implicit FTPS (port 990), the TLS handshake happens before the 220 banner.
Connect to the FTP server on port 21 to confirm you receive the 220 greeting. If the connection is refused or times out, the server is not running or a firewall is blocking port 21.
curl -v ftp://ftp.example.com/
Scan port 21 (FTP control) and port 990 (FTPS implicit) to verify they are reachable from your network.
Scan PortsFor FTPS servers, use openssl to connect and verify the TLS handshake succeeds. For explicit FTPS (port 21), use STARTTLS. For implicit FTPS (port 990), connect directly with TLS.
openssl s_client -connect ftp.example.com:990 -quiet
Ensure the FTP server hostname resolves to the correct IP address. If DNS is misconfigured, you may be connecting to the wrong server.
Check DNS RecordsThe FTP server is not ready yet but will be available shortly. The client should wait and retry.
The server is closing the FTP control connection in response to a QUIT command.
Authentication successful. The user is now logged in and can access the server.
The FTP server is unavailable and is closing the connection. The client should retry later.