Client could not connect to FileZilla server (2024)

The following error occurs when I use the domain name to access FileZilla server.
But when I use IP address to access FileZilla server, everything is fine.
And using https://ftptest.net/ to test the domain name was successful.
Thanks in advance for any help.

FilleZilla Cilent Message:
Status:Disconnected from server
Status:Resolving address of MyDomainName
Status:Connecting to DomainNameAddress...
Status:Connection established, waiting for welcome message...
Status:Initializing TLS...
Error:Could not connect to server
Status:Waiting to retry...
Status:Resolving address of MyDomainName
Status:Connecting to DomainNameAddress...
Status:Connection established, waiting for welcome message...
Response:220-FileZilla Server 1.8.1
Response:220-Please visit https://filezilla-project.org/
Response:220 Yes you did it!!!
Command:AUTH TLS
Response:234 Using authentication type TLS.
Status:Initializing TLS...
Error:Could not connect to server

FilleZilla Server Message:
Response: 220-FileZilla Server 1.8.1
Response: 220-Please visit https://filezilla-project.org/
Response: 220 Yes you did it!!!
Command: AUTH TLS
Response: 234 Using authentication type TLS.
Error: GnuTLS error -110: The TLS connection was non-properly terminated.
Status: Client did not properly shut down TLS connection
Error: Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.
Response: 220-FileZilla Server 1.8.1
Response: 220-Please visit https://filezilla-project.org/
Response: 220 Yes you did it!!!
Command: AUTH TLS
Response: 234 Using authentication type TLS.
Error: GnuTLS error -110: The TLS connection was non-properly terminated.
Status: Client did not properly shut down TLS connection
Error: Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.

botg wrote: ↑

2024-04-17 07:58

That's odd. Do you use any firewalls or virus scanners that perform TLS man-in-the-middle?

I have a TCP port forwarding service deployed on my cloud server.
It forwards all ports used by FileZillaServer on another server.
And here is the debugging information:

FilleZilla Cilent Message:

Status: Resolving address of MyDomainNameStatus: Connecting to DomainNameAddress...Status: Connection established, waiting for welcome message...Trace: CFtpControlSocket::OnReceive()Response: 220-FileZilla Server 1.8.1Response: 220-Please visit https://filezilla-project.org/Response: 220 Yes you did it!!!Trace: CFtpLogonOpData::ParseResponse() in state 1Trace: CControlSocket::SendNextCommand()Trace: CFtpLogonOpData::Send() in state 2Command: AUTH TLSTrace: CFtpControlSocket::OnReceive()Response: 234 Using authentication type TLS.Trace: CFtpLogonOpData::ParseResponse() in state 2Status: Initializing TLS...Trace: tls_layer_impl::client_handshake()Trace: tls_layer_impl::continue_handshake()Trace: TLS handshakep: About to send CLIENT HELLOTrace: TLS handshakep: Sent CLIENT HELLOTrace: tls_layer_impl::on_send()Trace: tls_layer_impl::continue_handshake()Trace: tls_layer_impl::on_read()Trace: tls_layer_impl::continue_handshake()Trace: CRealControlSocket::OnSocketError(106)Trace: CRealControlSocket::DoClose(66)Trace: CControlSocket::DoClose(66)Trace: CFtpControlSocket::ResetOperation(66)Trace: CControlSocket::ResetOperation(66)Trace: CFtpLogonOpData::Reset(66) in state 4Error: Could not connect to serverTrace: CFileZillaEnginePrivate::ResetOperation(66)Status: Waiting to retry...

FilleZilla Server Message:

Trace: Session XXXXXX with ID 680 created.Response: 220-FileZilla Server 1.8.1Response: 220-Please visit https://filezilla-project.org/Response: 220 Yes you did it!!!Command: AUTH TLSTrace: securer(1) ENTERING state = 0Trace: calling tls_layer_->set_certificate_file("PATH\certificate.key", "PATH\certificate.cer", "****")Trace: securer(1) EXITING state = 1Response: 234 Using authentication type TLS.Trace: ~securer(1) ENTERING state = 1Trace: calling tls_layer_->set_alpn()Trace: tls_layer_impl::server_handshake()Trace: tls_layer_impl::continue_handshake()Trace: ~securer(1) EXITING state = 2Trace: tls_layer_impl::on_send()Trace: tls_layer_impl::continue_handshake()Trace: tls_layer_impl::on_read()Trace: tls_layer_impl::continue_handshake()Trace: TLS handshakep: Received CLIENT HELLOTrace: TLS handshakep: Processed CLIENT HELLOTrace: TLS handshakep: About to send SERVER HELLOTrace: TLS handshakep: Sent SERVER HELLOTrace: TLS handshakep: About to send ENCRYPTED EXTENSIONSTrace: TLS handshakep: Sent ENCRYPTED EXTENSIONSTrace: TLS handshakep: About to send CERTIFICATETrace: TLS handshakep: Sent CERTIFICATETrace: TLS handshakep: About to send CERTIFICATE VERIFYTrace: TLS handshakep: Sent CERTIFICATE VERIFYTrace: TLS handshakep: About to send FINISHEDTrace: TLS handshakep: Sent FINISHEDTrace: tls_layer_impl::on_read()Trace: tls_layer_impl::continue_handshake()Trace: tls_layer_impl::failure(-110)Error: GnuTLS error -110: The TLS connection was non-properly terminated.Status: Client did not properly shut down TLS connectionError: Control channel closed with error from source 0. Reason: ECONNABORTED - Connection aborted.Trace: Session XXXXXX with ID 680 destroyed.

Thanks for reply.

botg wrote: ↑

2024-04-17 19:52

Do you still experience this issue if you don't use a third-party service?

Resolving the domain name to the IP address where FilezillaServer resides does not have this problem.

And the new question here is, why is https://ftptest.net/ accessible and Client not under the same conditions.

Thanks for reply.

Assuming the hostname resolves to the same IP, it doesn't make a different to FileZilla Server whether you entered the hostname or the IP address in the client. Technically the SNI in the TLS CLIENT HELLO is different, but the server does not make use of it.

I still think that there must be some third-party firewall or virus scanner that is interfering with the connection.

botg wrote: ↑

2024-04-18 08:46

Assuming the hostname resolves to the same IP, it doesn't make a different to FileZilla Server whether you entered the hostname or the IP address in the client. Technically the SNI in the TLS CLIENT HELLO is different, but the server does not make use of it.

I still think that there must be some third-party firewall or virus scanner that is interfering with the connection.

Thanks for your help！

According to your reply, I have re-checked the setting information in this respect.

The problem lies with the cloud server provider used for forwarding.

They set up an implicit firewall rule. It's about domain names

The problem was solved. Very thankful.