What should a SysOps administrator do to resolve this issue?
Create a new inbound rule on the EC2 instances’ security groups to allow ICMP traffic from the on-premises CIDR.
Create a peering connection between the IPsec tunnel and the subnet of the EC2 instances.
Enable route propagation for the virtual private gateway in the route table that is assigned to the subnet of the EC2 instances.
Modify the VPC’s DHCP options set. Add the IPsec tunnel to the VPN section.
Explanations:
Security group rules are used to control inbound and outbound traffic for EC2 instances, but the issue is likely related to routing rather than security group configurations. Modifying the security group to allow ICMP traffic would not resolve the issue of routing between the VPC and the on-premises network.
Peering connections are used to connect VPCs, not to route traffic between a VPC and an on-premises data center through an IPsec tunnel. Creating a peering connection would not address the IPsec tunnel setup or routing issues.
Enabling route propagation for the virtual private gateway ensures that the VPC route table learns the on-premises network routes through the IPsec tunnel. Without proper route propagation, the EC2 instances would not know how to route traffic to the on-premises resources.
Modifying the DHCP options set typically applies to settings such as DNS resolution, not routing. The issue at hand is routing between the VPC and the on-premises network, which would not be resolved by modifying DHCP options.
From what I’ve seen, the answer is:
Enable route propagation for the virtual private gateway in the route table that is assigned to the subnet of the EC2 instances.