12.0.0.0/6

Public

Class A — /6 prefix — 67,108,862 usable hosts

Network Address
12.0.0.0
Broadcast Address
15.255.255.255
Subnet Mask
252.0.0.0
Usable Hosts
67,108,862
First Usable IP
12.0.0.1
Last Usable IP
15.255.255.254
Total IPs
67,108,864
Prefix Length
/6

Network address — the base address of the block (12.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 15.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 67,108,862 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask252.0.0.0 is the dotted-decimal equivalent of /6. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 12.0.0.0/6
Network Address 12.0.0.0
Broadcast Address 15.255.255.255
Subnet Mask 252.0.0.0
Wildcard Mask 3.255.255.255
Prefix Length /6
IP Address Class Class A
Total IP Addresses 67,108,864
Usable Host Addresses 67,108,862
First Usable IP 12.0.0.1
Last Usable IP 15.255.255.254
Network (Hex) 0x0C000000
Broadcast (Hex) 0x0FFFFFFF
Address Type Public / Globally Routable

Binary Representation

Network Address
00001 00001100.00000000.00000000.00000000
Subnet Mask
11111100.00000000.00000000.00000000

The first 6 bits (1s in the mask) identify the network. The remaining 26 bits identify hosts within the network.

Split into Equal Subnets

Split 12.0.0.0/6 into 2 equal /7 subnets (33,554,430 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 12.0.0.0/7 12.0.0.0 12.0.0.1 13.255.255.254 13.255.255.255 33,554,430
2 14.0.0.0/7 14.0.0.0 14.0.0.1 15.255.255.254 15.255.255.255 33,554,430

/6 Subnet Reference

Total IPs 67,108,864
Usable Hosts 67,108,862
Subnet Mask 252.0.0.0
Wildcard 3.255.255.255

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