Unable to check whether cluster is sane: None of the configured nodes are available: [{#transport#-1}{eZzQC1GoSt-l8KSX-kk0bQ}{ip-10-11-1-200}{10.11.1.200:9300}] 06:28:17.502

Unable to check whether cluster is sane: None of the configured nodes are available: [{​​#transport#-1}​​{​​eZzQC1GoSt-l8KSX-kk0bQ}​​{​​ip-10-11-1-200}​​{​​10.11.1.200:9300}​​]
06:28:17.502 [elasticsearch[client][transport_worker][T#1]] ERROR com.floragunn.searchguard.ssl.transport.SearchGuardSSLNettyTransport - SSL Problem Received fatal alert: bad_certificate
javax.net.ssl.SSLException: Received fatal alert: bad_certificate
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1647) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1615) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.recvAlert(SSLEngineImpl.java:1781) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.readRecord(SSLEngineImpl.java:1070) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.readNetRecord(SSLEngineImpl.java:896) ~[?:1.8.0_201]
at sun.security.ssl.SSLEngineImpl.unwrap(SSLEngineImpl.java:766) ~[?:1.8.0_201]
at javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:624) ~[?:1.8.0_201]
at io.netty.handler.ssl.SslHandler$SslEngineType$3.unwrap(SslHandler.java:295) ~[netty-handler-4.1.32.Final.jar:4.1.32.Final]
at

Usually it means a certificate can’t be validated. Are you sure all certificates on all nodes were signed by the same CA? Here is a list of things for you to check, scroll to “Validating the certificate chain” https://docs.search-guard.com/latest/troubleshooting-tls#tls-troubleshooting