Cassandra connectivity issue

Author: Nikhil

Originally Sourced from: https://stackoverflow.com/questions/44069105/cassandra-connectivity-issue

I am new to cassandra. These are the resources with theirs' respected versions that i have used to set up cassandra. java : jdk1.8.0.111 cassandra : 3.10 ubuntu : 15.10

I have intsalled cassandra and made changes in the cassandra.yaml file. when i run cqlsh from editor then it shows following error: Connection error: ('Unable to connect to any servers', {'127.0.0.1': AuthenticationFailed('Remote end requires authentication.',)}) I tried my best to look at the issue but couldn't resolve it. can someone please help me in this.