After upgrading from SSH to SSH2, why do X11 tunneling, SCP, or SFTP not work any more?
While the Secure Shell V2 (SSH2) client is backwards compatible with SSH servers via emulation, some features and utilities do not work unless the server is also running SSH2. In particular, X11 tunneling, SCP, and SFTP will not work unless the server is also running SSH2. While the Unix SSH2 client will automatically search for and run SSH1 versions of these utilities, if present, the Windows client will not.
Last modified on May 10, 2011.