Sep-09-AWS-TGW-Same-Account-Diff-VPC

                                                                         TGW

AWS Transit Gateway provides a hub and spoke design for connecting VPCs and on-premises networks as a fully managed service without requiring you to provision third-party virtual appliances. No VPN overlay is required, and AWS manages high availability and scalability.

Transit Gateway enables customers to connect thousands of VPCs. You can attach all your hybrid connectivity (VPN and Direct Connect connections) to a single gateway, consolidating and controlling your organization's entire AWS routing configuration in one place (refer to the following figure). Transit Gateway controls how traffic is routed among all the connected spoke networks using route tables. This hub-and-spoke model simplifies management and reduces operational costs because VPCs only connect to the Transit Gateway instance to gain access to the connected networks.

Create a 3 VPC's:

-- Create VPC

-- Create Subnet

-- Create route table(Associate Subnets/ routes)

-- Create Internet Gateway. 

EX:-

Step-2:

Create Ec2 machines on VPC-1 & VPC-2 & VPC-3

Lunch machine on amazon linux3 machine.

dnf install httpd -y

systemctl enable httpd

systemctl start httpd

systemctl status httpd

cd /var/www/html

echo "This is the vpc1" >> index.html

Copy the public ip and test the local laptop:

http://52.66.89.106/

Step-3:

Create a TGW 

ASN make it default

CIDR make it default

Step-4:

Create TGW attachments for individual's VPC's

Like similar create vpc2 TGW attachment & VPC3 TGW attachment

Wait for the TGW attachment status should be available

Step-5:

Ensure properly add the route tables

VPC-1 Route table:

VPC-2 Route table:

VPC-3 Route table:

Step-6:

Lets test the connectivity:

Lets cross ping the vpc1 to VPC3 & VPC1 & vice versa