Since we updated our mac from 10.10 to 10.11 our tomcat can't connect anymore with the error
[SSH] Exception:Algorithm negotiation fail
This answer shows that we have to anable the diffie-hellman-group1-sha1 again:
sudo vi /private/etc/ssh/sshd_config
and added a line, because there was no line starting with "Ciphers"
but after restaring the daemon
sudo launchctl stop com.openssh.sshd; sudo launchctl start com.openssh.sshd;
i can't connect at all