101.0.0.0/12

Public

Class A — /12 prefix — 1,048,574 usable hosts

Network Address
101.0.0.0
Broadcast Address
101.15.255.255
Subnet Mask
255.240.0.0
Usable Hosts
1,048,574
First Usable IP
101.0.0.1
Last Usable IP
101.15.255.254
Total IPs
1,048,576
Prefix Length
/12

Network address — the base address of the block (101.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 101.15.255.255 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 mask255.240.0.0 is the dotted-decimal equivalent of /12. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 101.0.0.0/12
Network Address 101.0.0.0
Broadcast Address 101.15.255.255
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 101.0.0.1
Last Usable IP 101.15.255.254
Network (Hex) 0x65000000
Broadcast (Hex) 0x650FFFFF
Address Type Public / Globally Routable

Binary Representation

Network Address
01100101 01100101.00000000.00000000.00000000
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.

Subnet Breakdown — splitting into /13

This /12 block can be divided into 2 /13 subnets.

CIDR Network Broadcast First Usable Last Usable Hosts
101.0.0.0/13 101.0.0.0 101.7.255.255 101.0.0.1 101.7.255.254 524,286
101.8.0.0/13 101.8.0.0 101.15.255.255 101.8.0.1 101.15.255.254 524,286

/12 Subnet Reference

Total IPs 1,048,576
Usable Hosts 1,048,574
Subnet Mask 255.240.0.0
Wildcard 0.15.255.255

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