Once the network is properly configured, it is possible that you may have to open firewall rules to allow traffic between Cassandra nodes and clients. Remember that Cassandra requires the following ports to be opened for TCP traffic:
- 9042 native binary client protocol
- 7199 JMX
- 7000 internode communication
- 7001 internode communication via SSL
If you are using Cassandra 2.0 or an earlier version, some tools like cqlsh will still connect over port 9160 (Thrift protocol). Use of the Thrift protocol was reduced with Cassandra 2.2, and disabled by default as of Cassandra 3.0. With these newer versions, port 9160 is no longer required to be opened.
Depending on your cloud provider, you may or may not have cross-region communications ...
