Returns a list of DBSecurityGroup descriptions. If a DBSecurityGroupName is specified, the list will contain only the descriptions of the specified DB security group.

EC2-Classic was retired on August 15, 2022. If you haven't migrated from EC2-Classic to a VPC, we recommend that you migrate as soon as possible. For more information, see Migrate from EC2-Classic to a VPC in the Amazon EC2 User Guide, the blog EC2-Classic Networking is Retiring – Here’s How to Prepare, and Moving a DB instance not in a VPC into a VPC in the Amazon RDS User Guide.