(3) my notes on AWS Certified Solutions Architect Associate 2021 SAA-C02
CIDR notation
Published in
1 min readJan 9, 2022
x.x.x.x/32 means IP address x.x.x.x itself.
x.x.x.x/0 refers to the entire network.Amazon FSx for Lustre
- Lustre is a popular open-source parallel file system which stores data across multiple network file servers to maximize performance and reduce bottlenecks.- You use Lustre for workloads where speed matters, such as machine learning, high performance computing (HPC), video processing, and financial modeling.
Security groups vs ACL
security groups are stateful, so you only need to allow incoming traffic for certain ports.network ACL are stateless, so you have to explicitly grant inbound and outbound access.Rule number. Rules are evaluated starting with the lowest numbered rule. As soon as a rule matches traffic, it’s applied regardless of any higher-numbered rule that might contradict it.The client that initiates the request chooses the ephemeral port range. The range varies depending on the client's operating system.
Many Linux kernels (including the Amazon Linux kernel) use ports 32768-61000.For the MS SQL rule, change the Source to the security group ID attached to the application tier.
