6. In the Fulfilment Option drop-down list, select CloudFormation Template.
7. Select the relevant Software Version and then select Continue to Launch.
8. In the Launch this software page, select Launch CloudFormation in the Choose Action list and then select Launch. The Create stack/Specify template page opens.
9. Under Prepare template, select Template is ready.
10. Under Template source, choose Amazon S3 URL. Select the default Amazon S3 URL and select Next. The Specify stack details page opens.
11. Complete the Stack Details and Parameters. For Inbound Access CIDR, security groups act as a firewall for associated instances, controlling both inbound and outbound traffic at the instance level. Configuring Inbound Access CIDR allows you to add rules to a security group that enables you to connect to your Linux instance from your IP address using SSH:
If your IPv4 address is 203.0.113.25, specify 203.0.113.25/32 to list this single IPv4 address in CIDR notation. If your company allocates addresses within a range, specify the entire range, such as 203.0.113.0/24.
If you specify 0.0.0.0/0, it will enable all IPv4 addresses to access your instance using SSH.