> Also, don’t assign a EIP to your EC2 NAT instances (unless you absolutely must persist a given public IP) as that counterintuitively routes through public tra

> Also, don’t assign a EIP to your EC2 NAT instances (unless you absolutely must persist a given public IP) as that counterintuitively routes through public traffic. Just use a auto-assigned public IP (no EIP). Could you point me to somewhere I can read more about this? I didn't know there was an extra charge for using an EIP (other than for the EIP itself).