mqtt-exception : ssh handshake failed with openssl error - SSL_ERROR_ZERO_RETURN

[Kmoorthi1989]

HI Team,

I had provisioned MQTT "eclipse-mosquitto" docker on AWS+NLB for the MQTT broker and used MQTTnet for the communication to mqtt broker, client services are running in the same AWS region as docker container which is using "mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim".

Everything is working fine without TLS option, but when I enabled TLS (MQTTS) for the communication getting open SSL error "SSL_ERROR_ZERO_RETUN".

• Network Loadbalancer provides the TLS certificate for the TLS communication between client and loadbalancer but loadbalancer and mqtt broker communication is HTTP only.
• Update FQDN CA certificates into client docker images.
• I have tested MQTT CLI client tool, it was working using TLS.