Private subnet available IPv4 address showing 0, no service running

Hi Ankita,

Check Subnet Capacity: Go to the VPC Dashboard in the AWS Management Console. Select the VPC containing the problematic subnet. Navigate to the "Subnets" section and locate the private subnet. Check the "Available IPv4 addresses" column to see if it shows 0. If the subnet is running out of IP addresses, you may need to resize the subnet by adjusting the CIDR block or creating additional subnets.

Verify DHCP Configuration: Still in the VPC Dashboard, navigate to the "DHCP Options Sets" section. Ensure that the DHCP options set associated with your VPC is correctly configured. Check if the DHCP options set includes the correct DNS servers, domain name, and NTP servers. If necessary, create a new DHCP options set with the correct configurations and associate it with your VPC.

Inspect Network Interfaces: Go to the EC2 Dashboard and navigate to the "Network Interfaces" section. Check if there are any network interfaces attached to instances in the private subnet. Make sure that the network interfaces are associated with the correct subnet and have valid IPv4 addresses assigned to them.

Check Route Tables: Verify the route table associated with the private subnet. Ensure that the route table has a route to the internet gateway (if needed) or any other necessary destinations. Make sure that the route table is correctly configured to route traffic within the VPC and to external destinations.

Review Security Group Settings: Check the security group settings associated with the instances in the private subnet. Ensure that the security groups allow inbound and outbound traffic as required by your applications.