I've figured out that it is caused by this line in /etc/ssh/ssh_config
ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h
This was put there by the freeipa installer (ipa-client-install), so I guess this is a freeipa or sssd bug.
I've figured out that it is caused by this line in /etc/ssh/ssh_config
ProxyCommand /usr/bin/ sss_ssh_ knownhostsproxy -p %p %h
This was put there by the freeipa installer (ipa-client- install) , so I guess this is a freeipa or sssd bug.