VPC Routing
Here I am again with another micro concept in my Cloud Learning Series ☁️
So far, we covered:
✔️ What is a VPC?
✔️ VPC Subnetting
let’s continue the journey with:
👉 Route Tables in a VPC
Because creating subnets is not enough — We must decide how traffic moves.
In Amazon VPC, every VPC automatically comes with an implicit virtual router.
This router behaves like a physical router in a data center, but it is fully managed by AWS.
🔹 VPC Router & Interfaces
Each subnet inside a VPC has a router interface at:
👉 The first usable IP address of the subnet (usually x.x.x.1)
Example:
If subnet CIDR is x.x.x.0/24
Network address → x.x.x.0
Router interface → x.x.x.1
Note: AWS reserves 5 IP addresses in every subnet. (covered in VPC subnets topic)
🔹 Purpose of Routing in a VPC:
1️⃣ Subnets communicate with each other
2️⃣ Traffic move IN and OUT of the VPC
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🔹 Route Table
A Route Table is a 👉 set of rules (routes) that the VPC router uses to forward traffic.
Destn — — — match — — — point to target
eg: Packet leaves at subnet, checks for destination IP of packet find the matching route by checking destination
Each route contains:
Destination → CIDR block to match
Target → Where traffic should go
When a packet leaves a subnet:
It checks the destination IP
The router performs longest prefix match
Traffic is forwarded to the matching target
🔹 How It Works (Step-by-Step)
Create a VPC
Create subnets
Create or use a route table
Associate the route table with subnets
Add or edit routes (Destination + Target)
Cloud networking becomes clear when you understand the relationship between:
👉 VPC → Subnet → Route Table → Gateway
More cloud micro concepts coming soon 🚀
