configuring TLS setup but cant communicate between nodes using search guard plugin

i m using
-sesrch guard 6
-elasticsearch 6.1.2
-java version "1.8.0_25"

i want create 3 nodes cluster. for that i generated node certificates (.jks format) signed by the root CA and placed in both nodes. all the nodes individually work fine, but they cant communicate between themselves. they continuosly ping each other.

in node 1 getting error:

[ERROR][c.f.s.s.t.SearchGuardSSLNettyTransport] SSL Problem Recieved fatal alert:internal_error Received fatal alert: internal_error

in node 2 getting error:
Caused the trustAnchor parameter must be non empty

then i removed all the generated certificate (.jks format) and used the demo certificate (root-ca.pem and other pem certificates for nodes) and also enable this searchguard.authcz.admin_dn:


in elasticsearch.yml file

this time it is saying that node1 is unable to connect with node2 and in node2 it is saying that node2 is unable to join with node1 and they continously pinging each other.

pls give me the solution.