Module-4 Networking
- Amazon Virtual Private Cloud (VPCs) — lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network.
- Subnet — a section of a VPC that can contain resources such as Amazon EC2 instances.
- Public subnets — contain resources that need to be accessible by the public, such as an online store’s website.
- Private Subnet — contain resources that should be accessible only through your private network, such as a database
- The public subnets have access to the internet gateway; the private subnets do not.
- Internet Gateway — To allow traffic from the public internet to flow into and out of your VPC
- Private Gateway (called virtual private gateway) — allows to create a VPN connection between a private network and to your VPC, in order to access internal AWS resources.
- AWS Direct Connect is a service that enables you to establish a dedicated private connection between your data center and a VPC.
Network traffic in VPC
- When a customer requests data from an application hosted in the AWS Cloud, this request is sent as a packet.
- The VPC component that checks packet permissions for subnets is a network access control list (ACL). It is a virtual firewall that controls inbound and outbound traffic at the subnet level.
- Network ACLs perform stateless packet filtering. They remember nothing and check packets that cross the subnet border each way: inbound and outbound.
- The VPC component that checks packet permissions for an Amazon EC2 instance is a security group. — It is a virtual firewall that controls inbound and outbound traffic for an Amazon EC2 instance.
- Security groups perform stateful packet filtering. They remember previous decisions made for incoming packets.
The two AWS services that helps in the case of websites are -
- Amazon Route 53 is a DNS web service. It gives developers and businesses a reliable way to route end users to internet applications hosted in AWS.
- It can be used to register domain names as well as direct traffic to different endpoints.
- It connects user requests to infrastructure running in AWS.
- Amazon CloudFront — It helps to speed up delivery of website assets to customers.
