Problem with check_by_ssh check_mk and icinga

Hi,I have a problem with plugin check_by_ssh, and all checks work fine but always get a error aleatory.

In mi environment, I have 40 check_by_ssh in each server and get this error:

Remote command execution failed: ssh_exchange_identification: Connection closed by remote host

I suppose the problem succeed when the check is executed in same time and moment for all services.

Any have idea for this problem, I check on google but I cant fix this.



searching for this brings several possible reasons and solutions, here are the first ones:

…it’s no issue with check_mk or icinga, just an SSH one.


Yes, I have found the solution the problem is the concurrent ssh connections, In my configuration of sshd add the next line:

MaxStartups 50:30:100

50 concurrent connections