Virtual Private Cloud (VPC):
A Virtual Private Cloud (VPC) is a logically isolated section of the cloud where you can launch and manage resources like virtual machines, databases, and containers. It allows you to create a private network within the public cloud infrastructure. Each VPC has its own IP address range, subnets, routing tables, security groups, and other network-related settings.
Key features of a VPC include:
Isolation: VPCs provide network isolation, allowing you to create multiple separate environments within the same cloud provider account.
IP Address Range: Each VPC is associated with an IP address range, which you can segment into smaller subnets to isolate different components or services.
Subnets: Subnets are subdivisions of a VPC's IP address range. They can be public (accessible from the internet) or private (accessible only within the VPC).
Security Groups: Security groups act as virtual firewalls, controlling inbound and outbound traffic to instances within a VPC.
Network Access Control Lists (NACLs): NACLs are another layer of security that control traffic at the subnet level.
Route Table:
A Route Table is a configuration that determines how network traffic is directed within a VPC. It defines the rules for routing traffic from one subnet to another or to external destinations like the internet.
Key aspects of a Route Table include:
Routes: A route table contains a list of routes, where each route specifies a destination (usually a CIDR block) and a target (where the traffic should be sent).
Default Route: A default route is a catch-all route used when no specific route matches the destination. It's often used to direct traffic to the internet gateway for external access.
Associations: Each subnet in a VPC is associated with a specific route table. This determines how traffic is routed within that subnet.
Propagation: Some services within the cloud platform, like Virtual Private Gateway (for VPN connections) or Transit Gateway, can propagate routes to your custom route tables.
Public and Private Subnets: Route tables are often used to control whether a subnet is public (accessible from the internet) or private (not directly accessible from the internet).