Dear WinSCP Team,
I am writing to report a persistent connection issue I am encountering when using WinSCP to upload files to my Xiaomi Router BE6500 (which runs a customized OpenWrt/BusyBox system with Dropbear SSH).
The Issue:
When uploading files using the SCP protocol, I consistently receive the error:
Network error: Software caused connection abort
Behavior Details:
Login and directory listing work perfectly.
The error occurs specifically during the file data transfer phase.
I can confirm that the transfer starts, and a file (with 0 or partial size) is created on the server side before the connection drops.
The Anomaly:
The behavior is highly dependent on the target directory, which is very strange:
Uploading to
/data/userdisk -> Success.
Uploading to
/data/userdisk/data -> Fails with the error above.
(Note: Both directories appear to have identical permissions rwxr-xr-x).
Troubleshooting Attempts:
I have tried enabling almost all compatibility options to mimic a "dumb" SCP client, but none of the following settings resolved the issue:
- Unchecked "Optimize connection buffer size"
- Unchecked "Lookup user groups"
- Disabled "Enable transfer resume/transfer to temporary filename"
- Unchecked "Preserve timestamp"
- Unchecked "Set permissions"
- Unchecked "Encrypt new files"
- Unchecked "Calculate total size"
- Set Shell to
/bin/sh
Comparison (Control Group):
Crucially, the file transfer works perfectly to the exact same destination (
/data/userdisk/data) when using:
Windows built-in OpenSSH client:
scp -O source target works fine.
MobaXterm: Works fine.
Environment:
Local OS: Windows 10 Enterprise 22H2 (Build 19045)
WinSCP Version: 6.5.5 (Build 16453). Note: The issue persists in version 6.5.5 and multiple older versions.
Remote Device: Xiaomi Router BE6500 (XiaoQiang)
Transfer Protocol: SCP
It appears that WinSCP's implementation conflicts with the router's SCP server in this specific scenario, even with all "smart" features disabled.
Attached are the session logs for your reference.
Best regards