Orchestrator - Run SSH fails with hardened Linux Machines
System Center Orchestrator has a built in activity for running SSH on remote machines. You may find that working runbooks start failing on new distributions of linux or with hardened machines.
Orchestrator’s ssh is simply calling the command-line version of putty (called plink) from the C drive of the Runbook Server. The executable is located in:
“C:\Program Files (x86)\Common Files\Microsoft System Center 2012\Orchestrator\Extensions\Support\SSH”
You may find that the problem you are experiencing is that the versions of plink that shipped with Orchestrator don’t support the more modern and hardened cyphers that are becoming standard for ssh tunnelling.
The most current versions of Plink may be downloaded here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Downloading a recent version and renaming it to SshClient.exe (and copying to the directory above) resolves the cypher issues.