Connection refused when master starting agend with 1.4.1

[hudi1]

We are moving faban to newer version. But when we want to start agent there is connection refused exception. How to debug this problem. I saw we start connection just on tcp6. It is problem ?

Agent(Daemon) starting agent with options: [my-ip.a.b, 192.168.96.104, 192.168.96.103, /usr/lib/jvm/java-11-openjdk-11.0.2.7-0.el7_6.x86_64, -Dfaban.home=/app/faban/, -Djava.security.policy=/app/faban/config/faban.policy, -Djava.util.logging.config.file=/app/faban/config/logging.properties, -Dfaban.registry.port=9998, -Dfaban.logging.port=9999, -Xmx1g, -Xms256m, -XX:+DisableExplicitGC, faban.benchmarkName=rob-benchmark, faban.download=http://192.168.96.104:9980/, /, :]
java.rmi.ConnectException: Connection refused to host: 192.168.96.104; nested exception is: 

[whitingjr]

This issue should now be solved. Try re-instating the prior version of the file named bin/Linux/interfaces. This should get your installation working until the next release.