This article covers method to fix AWS Instance loses network connectivity error.
Basically, AWS Instance loses network connectivity if the instance has the wrong time set.
To fix Amazon EC2 Windows instance network connectivity issue:
You can create a temporary elastic network interface, and attach the network interface to the Amazon EC2 Windows instance. Then, you can temporarily connect to the instance and fix the issue.
1. Open the Amazon EC2 console, and then choose Instances from the navigation pane.
2. Select your instance. From the Description tab, note the Subnet ID.
3. Create a new network interface in the same subnet as the instance.
Important: Be sure to select a security group that allows incoming Remote Desktop Protocol (RDP) traffic from your IP address.
4. Attach the new network interface to the instance.
Note: The network interface might take a few minutes to come online. If you connect to the instance using RDP, associate an Elastic IP address with the network interface.
5. Using the new network interface, connect to the instance using RDP.
6. Change the network connection settings in Windows to use DHCP. Or, specify the correct private IP address settings. For instructions, see Configuring a secondary private IPv4 address for your Windows instance.
7. Detach the temporary network interface.
Note: If you've associated an Elastic IP address with the network interface, and no longer need the Elastic IP address, release the Elastic IP address.