IPRangeExplorer

10.96.0.0/12

Private (RFC 1918) RFC 1918

The 10.96.0.0/12 range is the default service CIDR used by kubeadm-bootstrapped Kubernetes clusters. All ClusterIP Services get a virtual IP from this range. The range covers 10.96.0.0 through 10.111.255.255 — over 1 million addresses — providing headroom for large clusters.

Network Address
10.96.0.0
Broadcast Address
10.111.255.255
Subnet Mask
255.240.0.0
Usable Hosts
1,048,574
First Usable IP
10.96.0.1
Last Usable IP
10.111.255.254
Total IPs
1,048,576
Prefix Length
/12

Network address — the base address of the block (10.96.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 10.111.255.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 1,048,574 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.240.0.0 is the dotted-decimal equivalent of /12. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 10.96.0.0/12
Network Address 10.96.0.0
Broadcast Address 10.111.255.255
Subnet Mask 255.240.0.0
Wildcard Mask 0.15.255.255
Prefix Length /12
IP Address Class Class A
Total IP Addresses 1,048,576
Usable Host Addresses 1,048,574
First Usable IP 10.96.0.1
Last Usable IP 10.111.255.254
Network (Hex) 0x0A600000
Broadcast (Hex) 0x0A6FFFFF
Governing RFC RFC 1918
Address Type Private (RFC 1918)

Binary Representation

Network Address
00001010 00001010.01100000.00000000.00000000
Subnet Mask
11111111.11110000.00000000.00000000

The first 12 bits (1s in the mask) identify the network. The remaining 20 bits identify hosts within the network.

Split into Equal Subnets

Split 10.96.0.0/12 into 2 equal /13 subnets (524,286 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 10.96.0.0/13 10.96.0.0 10.96.0.1 10.103.255.254 10.103.255.255 524,286
2 10.104.0.0/13 10.104.0.0 10.104.0.1 10.111.255.254 10.111.255.255 524,286

Common Use Cases

  • → Kubernetes ClusterIP service virtual IPs
  • → kube-dns service (typically 10.96.0.10)
  • → kubeadm default --service-cidr value
  • → Service network planning to avoid VPC overlap

Code Examples

Terraform 
# Terraform — EKS cluster with custom service CIDR
resource "aws_eks_cluster" "main" {
  name     = "main"
  role_arn = aws_iam_role.eks.arn

  vpc_config {
    subnet_ids = var.subnet_ids
  }

  kubernetes_network_config {
    service_ipv4_cidr = "10.96.0.0/12"
    ip_family         = "ipv4"
  }
}
Shell / CLI 
# kubeadm init — specify service CIDR explicitly
kubeadm init \
  --service-cidr 10.96.0.0/12 \
  --pod-network-cidr 10.244.0.0/16

# Check current service CIDR on a running cluster
kubectl cluster-info dump \
  | grep -m1 service-cluster-ip-range

/12 Subnet Reference

Total IPs 1,048,576
Usable Hosts 1,048,574
Subnet Mask 255.240.0.0
Wildcard 0.15.255.255
Full /12 reference →

Related Ranges

Parent /11 block 10.96.0.0/11 Sibling /12 block 10.112.0.0/12

Adjacent Prefix Sizes

/10 4,194,302 hosts /11 2,097,150 hosts /12 1,048,574 hosts /13 524,286 hosts /14 262,142 hosts

Calculate Another