Use the service name
cassandra00 for the hostname per the docker-compose documentation https://docs.docker.com/compose/compose-file/#links
Containers for the linked service are reachable at a hostname identical to the alias, or the service name if no alias was specified.
CASSANDRA_LISTEN_ADDRESS envvar unset (or pass
auto) per https://docs.docker.com/samples/library/cassandra/
The default value is auto, which will set the listen_address option in cassandra.yaml to the IP address of the container as it starts. This default should work in most use cases.