IPRangeExplorer

128.0.0.0/2

Public

Class B — /2 prefix — 1,073,741,822 usable hosts

Network Address
128.0.0.0
Broadcast Address
191.255.255.255
Subnet Mask
192.0.0.0
Usable Hosts
1,073,741,822
First Usable IP
128.0.0.1
Last Usable IP
191.255.255.254
Total IPs
1,073,741,824
Prefix Length
/2

Network address — the base address of the block (128.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 191.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 1,073,741,822 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 192.0.0.0 is the dotted-decimal equivalent of /2. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 128.0.0.0/2
Network Address 128.0.0.0
Broadcast Address 191.255.255.255
Subnet Mask 192.0.0.0
Wildcard Mask 63.255.255.255
Prefix Length /2
IP Address Class Class B
Total IP Addresses 1,073,741,824
Usable Host Addresses 1,073,741,822
First Usable IP 128.0.0.1
Last Usable IP 191.255.255.254
Network (Hex) 0x80000000
Broadcast (Hex) 0xBFFFFFFF
Address Type Public / Globally Routable

Binary Representation

Network Address
1 10000000.00000000.00000000.00000000
Subnet Mask
11000000.00000000.00000000.00000000

The first 2 bits (1s in the mask) identify the network. The remaining 30 bits identify hosts within the network.

Split into Equal Subnets

Split 128.0.0.0/2 into 2 equal /3 subnets (536,870,910 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 128.0.0.0/3 128.0.0.0 128.0.0.1 159.255.255.254 159.255.255.255 536,870,910
2 160.0.0.0/3 160.0.0.0 160.0.0.1 191.255.255.254 191.255.255.255 536,870,910

/2 Subnet Reference

Total IPs 1,073,741,824
Usable Hosts 1,073,741,822
Subnet Mask 192.0.0.0
Wildcard 63.255.255.255
Full /2 reference →

Related Ranges

Parent /1 block 128.0.0.0/1 Sibling /2 block 192.0.0.0/2

Adjacent Prefix Sizes

/0 4,294,967,294 hosts /1 2,147,483,646 hosts /2 1,073,741,822 hosts /3 536,870,910 hosts /4 268,435,454 hosts

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