There are some firewall rules that may not supported on a cluster, but are currently open to networking traffic. It may be due to various of reasons, such as upgrading or downgrading cluster from a different version. If these rules exist on a cluster, Instaclustr will display them as a table in the Firewall Rules setting page. It is recommended you review these rules and if appropriate remove them, in order to improve security. You can do this by clicking the button labelled Remove all unsupported rules. This will irrecoverably remove all of the unsupported rules.
Firewall Rule Type(s) That Are Unsupported
Cassandra Thrift Rules in Cassandra 4
As Thrift API is deprecated in the Cassandra 4, Cassandra Thrift Rules will not be supported in our Cassandra 4 cluster. However, if the cluster has been upgraded from Cassandra 3, then the old rules will still exist until the user removes them.