After upgrading a linux server to openssh 6.7, I'm no longer able to connect to it from MS Windows (winswitch 0.12.20). In the server's log I see "fatal: Unable to negotiate a key exchange method [preauth]". I have no trouble connecting to the server via putty.

It seems that this is a twisted-conch issue: ​http://twistedmatrix.com/trac/ticket/7672

However, I assume that even once that's fixed, some work will be required on winswitch's part, too, even if only to create a new build; so opening a ticker here, too.

I need to use Win7 Ultimate machine as server for applications and Lubuntu 12.10 as client. The problem is i don't see any applications available to launch in tray icon menu - not in Windows 7 neither Lubuntu. Sure i connected to server and vice-versa. I tried to match same protocol - nx on Win7 and Linux, but no result. When checking connection configuration i see this -

Seamless Default "None available! Microsoft Microsoft Windows limitations"

Desktop Default "None available! Microsoft Microsoft Windows limitations" So i assume the problem in Win 7 Ultimate support. I used before to connect to Windows 2003 Server from Gentoo and it just worked fine.

The Windows plink binary needs updating as it has very limited MAC algorithm support and newer Linux distros have disabled those by default.

Log connecting to an Ubuntu 15.04 server: sshd[27346]: fatal: no matching mac found: client hmac-sha1,hmac-md5 server hmac-sha2-512-etm@…,hmac-sha2-256-etm@…,umac-128-etm@…,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160 [preauth]