I have NRPE daemon process running under xinetd on amazon ec2 instance and nagios server on my local machine.
The check_nrpe -H [amazon public IP] gives this error:
CHECK_NRPE: Error - Could not complete SSL handshake.
Both Nrpe are same versions. Both are compiled with this option:
./configure --with-ssl=/usr/bin/openssl --with-ssl-lib=/usr/lib/i386-linux-gnu/
"allowed host" entry contains my local IP address.
What could be the possible reason of this error now??
So many answers, none of them hit the reason why I ran into this issue.
It turns out that nagios has terrible cross-version support and this was caused by me having a version 2 "client" (machine being monitored) and a version 3 "server" (monitoring machine).
Once I upgraded the client to version 3, the problem went away and I could do a check_nrpe -H [client IP] without issues.
Note that I am not sure if client/server are the right terms with nagios, as in the case of an NRPE call, the server is really the machine being called, but I digress.
SSL handshake error msg.Beside the allow_host you should assign.
your nagios server is in a local lan with C type ip address such as 192.168.xxxx
when the target monitored server feedback the ssl msg to your local nagios server,the message should first comes to your public IP of your line,the message cannot across the public IP into your nagios server which ip is an internal one.
you need NAT to guide the SSL message from target server to inner nagios server.
Or you better use "GET" method which just get monitor message from the nagios client side,such as SNMP to fulfill the remote monitor of local resource of linux servers.
SSL need feedback in double direction.
Best Regards
check configuration in /etc/xinetd.d/nrpe and verify the server IP. If it is showing only_from = 127.0.0.1 change it with Server IP .