...
There is a default security group that cannot be deleted, however it can have rules added and removed from it. Additional security groups can also be created depending on need. When a new Rapid Access Cloud account is created, the default security group is empty and has four rules. The Egress rules, traffic going out from the instance, is permitted to go out by default. The Ingress rules, traffic going in to the instance, is denied by default since it does not specify any network as seen in the Remote IP Prefix. Thus, a few rules are required to permit basic access.
Modify the default security group
...