When setting up an FTP site using IIS (Internet Information Services), you may encounter the following FTP error in FileZilla:

Command:	TYPE I
Response:	200 Type set to I.
Command:	PASV
Error:	Disconnected from server: ECONNABORTED - Connection aborted
Error:	Failed to retrieve directory listing

This error typically occurs due to passive mode FTP communication issues, especially behind firewalls or NAT routers.

Solution: Fix FTP Directory Listing Error in FileZilla

Follow these steps to resolve the issue:

1. Open FileZilla

2. Navigate to Edit > Settings

3. Under Connection > FTP, select:
   ✅ Active (instead of Passive)

4. Under Connection > FTP > Active Mode, choose:
   ✅ “Ask your operating system for the external IP address”

5. Under Connection > FTP > Passive Mode, select:
   ✅ “Fall back to active mode”

6. Click OK to save settings.

7. Try reconnecting to your FTP server.

Why This Works:

• Passive mode requires the server to open a new port for directory listing, which is often blocked or misrouted by firewalls or NAT.

• Active mode allows the client to initiate both control and data connections, avoiding such issues in many local setups.

Best Practices for IIS FTP Configuration:

• Make sure the FTP firewall support module in IIS is configured with a data channel port range and external IP.

• Ensure your router/firewall has port forwarding set for the FTP data ports.

• If using SSL, ensure that FTP over TLS settings are correct in both IIS and FileZilla.