Cannot connect to Cassandra

[Jean-Nicolas Boulay Desjardins]

My Cassandra used to work with no problems.

I was able to connect with no problems but now for some reason it doesn't
work anymore.

[default@unknown] connect localhost/9160;
Exception connecting to localhost/9160. Reason: Connection refused.

and

root# ./bin/cassandra-cli -host localhost -port 9160
Exception connecting to localhost/9160. Reason: Connection refused.

Thanks in advance...