WEB Sever - Frequent Disconnect Issue

Based on the symptoms you've described, it appears your AWS-hosted server is experiencing intermittent connectivity issues that are affecting both remote access and website availability. This type of problem can have several potential causes at the infrastructure and network level. Here are some areas to investigate:

1. Instance Health: Check the EC2 instance status in the AWS console to ensure it's in a "running" state and passing all status checks. Sometimes, underlying hardware issues can cause intermittent connectivity problems.

2. Network Configuration: Verify that your security groups, network ACLs, and VPC settings are correctly configured and haven't been inadvertently changed. Misconfigured network settings can lead to sporadic connectivity issues.

3. Resource Utilization: Monitor your instance's resource usage using AWS CloudWatch. Look for any spikes in CPU, memory, or disk usage that could be causing the instance to become unresponsive. Even if CPU usage appears normal during RDP sessions, there might be periodic spikes causing issues.

4. Instance Type and Credit Balance: If you're using a burstable instance type (like t2 or t3), check your CPU credit balance. When these instances exhaust their CPU credits, performance can degrade, leading to connectivity issues.

5. Elastic IP: Consider associating an Elastic IP with your instance if you haven't already. This can help maintain a consistent public IP address and potentially mitigate some connectivity issues.

6. Auto-recovery: Enable the auto-recovery feature for your EC2 instance. This will automatically recover the instance if it becomes impaired due to underlying hardware issues.

7. Region or Availability Zone Issues: Check the AWS Service Health Dashboard to see if there are any reported issues in your region that might be affecting your instance.

If these steps don't resolve the issue, you may want to consider:

1. Instance Recovery: Try stopping and starting the instance (not just rebooting) to move it to new underlying hardware. This can sometimes resolve persistent issues.

2. Creating an AMI: Create an Amazon Machine Image (AMI) of your current instance and launch a new instance from this AMI. This can help determine if the issue is specific to the current instance or if it persists on new hardware.

3. Detailed Monitoring: Enable detailed monitoring temporarily to get more granular data on your instance's performance, which could help identify patterns or specific times when issues occur.

Given the business impact of these disruptions, it's advisable to engage AWS Support directly if these steps don't resolve the issue. They can provide more in-depth analysis of your specific instance and the underlying infrastructure.
Sources
EC2 suddenly gets online and offline randomly | AWS re:Post
Connectivity Issue to EC2 Instances | AWS re:Post
Recurring Website Access Issues with Amazon Lightsail Instance | AWS re:Post