You have Instances in a private subnet in a VPC. You have provisioned a NAT gateway in a public subnet to allow for instances in the private subnet to communicate with the Internet. You are trying to ping the Elastic IP of the NAT gateway from your workstation, but cannot do so. What can be done to resolve this issue?

Answer options:

A.Change the Security Groups assigned to the NAT gateway to allow Incoming ICMP traffic.
B.Change the NACLs assigned to the public subnet hosting the NAT gateway to allow Incoming and outgoing ICMP traffic.
C.Ping the public IP address of the NAT gateway instead of the Elastic IP.
D.This is not possible, since this is how the NAT gateway works.

Answer – D
The AWS Documentation mentions the following to support this.
NAT Gateway Doesn`t Respond to a Ping Command
If you try to ping a NAT gateway`s Elastic IP address or private IP address from the internet (for example, from your home computer) or from any instance in your VPC, you do not get a response. A NAT gateway only passes traffic from an instance in a private subnet to the internet.
To test that your NAT gateway is working, see Testing a NAT Gateway.
Option A is incorrect since there is no concept of Security Groups for NAT gateways.
Option B is incorrect since changing the NACLs is not the right approach.
Option C is incorrect since the NAT gateway gets an Elastic IP.
For more information on troubleshooting NAT gateways, please refer to the below URLs
https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-gateway.html#nat-gateway-troubleshooting
https://docs.aws.amazon.com/vpc/latest/userguide/nat-gateway-troubleshooting.html#nat-gateway-troubleshooting-ping