Conclusion

Throughout this lab, we have set up a low-budget NAT instance which is a cost-effective alternative to the NAT Gateway in development and testing environments. It has met the requirements of allowing the instances in the private subnets to access the internet through the NAT instance. Additionally, the NAT instance is automatically recovered if it is terminated (intentionally or unintentionally) due to the Auto-Scaling Group.

Although the NAT instance is a cost-effective solution, it has some limitations compared to the NAT Gateway:

• Scalability: The NAT instance does not scale automatically. You need to set up an Auto-Scaling Group to ensure that the NAT instance is replaced automatically if it is terminated.
• Maintenance: The NAT instance requires maintenance, such as patching, monitoring, and replacing the instance if it fails.
• Performance: The NAT instance performance depends on the instance type you choose. If you choose a small instance type, it may not handle the traffic efficiently.

Depending on your use case, you may need to consider these limitations and choose the appropriate solution.