How can I activate IPv6 for a currently running EC2 instance and establish an SSH connection utilizing IPv6?

Hi Deepak, the steps you need to take is enable IPv6 addressing in your VPC, update the routing table for the subnet where the EC2 is with IPv6 default routing to internet gateway, finally ensure the security group assigned to your EC2 allows SSH over IPv6 from a known source (Your SSH terminal). Your SSH terminal must be enabled with IPv6 and the source IP is your IPv6.

Here is a good place to start with to enable IPv6 in your VPC: https://docs.aws.amazon.com/vpc/latest/userguide/vpc-migrate-ipv6.html

Then to enable IPv6 in your EC2, Check this: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-instance-addressing.html#working-with-ipv6-addresses

I also recommend to review this Question: https://repost.aws/questions/QUjvFjzRUDQRmoUawpN1GZIw/can-t-ssh-to-ec2-instance-with-ipv6-address#ANSwlK7GdFTKeE0oNSa13MSg for troubleshooting.

Hello,

Enabling IPv6 on an existing EC2 instance involves several key steps.

Here is a step-by-step guide to enabling IPv6 on an existing EC2 instance and establishing an SSH connection using IPv6:

1. Enable IPv6 in VPC Settings: Start by adding a new IPv6 CIDR to your Virtual Private Cloud (VPC).
2. Add IPv6 Subnet to EC2 Subnet: Identify the subnet where your EC2 instance is located and add an IPv6 subnet to it.
3. Assign IPv6 Address: Associate an IPv6 address with your EC2 instance using either the AWS Management Console or the AWS CLI.
4. Add IPv6 Default Route to Subnet Routing Table with IGW Destination: Update the routing table associated with the subnet to include a default route for IPv6 with the Internet Gateway (IGW) as the destination.
5. Update Security Group: Modify the security group linked to your EC2 instance to permit incoming IPv6 traffic on the SSH port (default is 22). If there is no existing inbound rule for IPv6, create one."That will expose the internet to the internet so Try to Limit the Source in the Security Group"
6. SSH Connection: With IPv6 now enabled, use the assigned IPv6 address to establish an SSH connection to your EC2 instance.

This is Also a Good Reference: https://aws.amazon.com/blogs/networking-and-content-delivery/dual-stack-ipv6-architectures-for-aws-and-hybrid-networks/