🌐 Routing and Route Tables: How Network Traffic Finds Its Way

After understanding IP addresses and MAC addresses, the next important networking concept is routing. Routing is the process of deciding where network packets should go to reach their destination. A router uses the destination IP address and routing information to choose the appropriate path.

A route is basically a rule that says where traffic should be sent. For example, if a device wants to communicate with another network, the router checks the destination IP and decides which next path or gateway should handle the traffic.

A route table contains multiple routing rules. Each rule generally has a destination and a target. For example, in AWS, a route such as 0.0.0.0/0 → Internet Gateway means traffic for destinations not otherwise matched can be sent toward the Internet Gateway.

In AWS, a subnet whose route table has a route to an Internet Gateway is considered a public subnet. A subnet without such a route is considered a private subnet. Private resources can still access the internet through a NAT Gateway when the architecture requires outbound access without allowing unsolicited inbound connections.

Think of routing like Google Maps. Your destination is the IP address, the route table is the map, and the router chooses the path. In AWS, VPCs, subnets, route tables, Internet Gateways, and NAT Gateways work together to control how applications communicate.

Understanding routing is an important step toward learning AWS VPC, public/private subnets, NAT Gateway, security groups, and cloud networking. 🚀