CompTIA Cloud+ (CV0-004)TroubleshootingEasy
A cloud engineer is trying to deploy a new virtual machine (VM) from a custom image in a specific subnet. The deployment consistently fails with an error indicating 'Insufficient IP addresses in subnet'. The subnet currently has 20 free IP addresses, and the VM requires only one. What is the MOST likely reason for this deployment failure?
- AThe subnet's CIDR block is too small to accommodate any new VM deployments.
- BThe VM's network interface is configured to request multiple IP addresses.
- CThe custom image is too large, exceeding the maximum size allowed for the subnet.
- DThe cloud provider reserves a certain number of IP addresses in each subnet for internal use.
Show answer & explanationAnswer & explanation
Correct answer: D. The cloud provider reserves a certain number of IP addresses in each subnet for internal use.
Cloud providers typically reserve a few IP addresses in each subnet for internal network infrastructure (e.g., network gateway, DNS, broadcast), even if the reported 'free' count doesn't explicitly subtract them. This can lead to 'insufficient IP' errors when the actual usable IPs are fewer than expected.
Why the other options are wrong
- A. If 20 IPs are free, the CIDR block is not 'too small' in general, but usable IPs might be an issue.
- B. While possible, a VM typically requests one primary IP. If it requested multiple, the error might be more specific or the administrator would be aware.
- C. Image size is related to storage, not IP address availability within a subnet.
Reserved IP Addresses (Subnet)
Specific IP addresses within a subnet's CIDR range that are reserved by the cloud provider for internal network services and cannot be assigned to customer resources.
- Typically includes network address, broadcast address, and gateway.
- Often includes addresses for DNS or other service endpoints.
- Reduces the number of usable IP addresses for VMs/containers.
Memory trick: Reserved IPs Reduce Available Spots.