FTP Client "Connection Timeout"

pierre shiraziefard 165 Reputation points
2026-02-19T16:10:28.1266667+00:00

hello,

I have a public facing FTP resource I am trying to setup.

I have configured this vm for FTP access, configured the vm firewall rules correctly, setup inbound rules correctly on azure.

using passive ftp

Yet using filezilla as test, logs in successfully but fails on retrieving directory with "connection timeout" I confirmed its connecting using passive mode (pic attached)

Need help in getting this service working for us.

Azure Firewall
Azure Firewall

An Azure network security service that is used to protect Azure Virtual Network resources.


Answer accepted by question author
Vallepu Venkateswarlu 10,595 Reputation points Microsoft External Staff Moderator
2026-02-19T16:47:59.3366667+00:00

Hi @ pierre shiraziefard,

Welcome to Microsoft Q&A Platform.

This issue is consistent with passive FTP data channel connectivity restrictions and is not related to authentication or an FTP service failure. Once the passive port range is properly defined and allowed through all firewall layers (FTP service configuration, OS firewall, and Azure NSG), directory listing should function normally.

Adding the following details based on logs:

The issue is not related to authentication or the Azure NSG on port 21. The problem lies with the passive data port.

The calculation (11 × 256) + 185 = 3001 indicates that the client is attempting to connect to: 20.X.X.44:3001

This connection is currently being blocked.

To resolve the issue passive data ports must be allowed.

  • Configure a fixed passive port range 49152-65535 in IIS.
  • Open only that defined port range in IIS
  • Allow the Port 21 and 49152-65535 in Azure Network Security Group.
  • Windows Firewall

Once the passive port range is consistently configured and permitted across all layers, FTP directory listing should work as expected.

Follow the Server 2012 VM on Azure - Passive FTP Won't Work & How to set up FTP on Azure VM for more troubleshoot.

Note: If the information above did not help to resolve the issue, kindly share the requested details in a private message for further troubleshoot.

Please210246-screenshot-2021-12-10-121802.pngand “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

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