IPRangeExplorer

151.8.138.0/23

Public

Class B — /23 prefix — 510 usable hosts

Network Address
151.8.138.0
Broadcast Address
151.8.139.255
Subnet Mask
255.255.254.0
Usable Hosts
510
First Usable IP
151.8.138.1
Last Usable IP
151.8.139.254
Total IPs
512
Prefix Length
/23

Network address — the base address of the block (151.8.138.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 151.8.139.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 510 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.255.254.0 is the dotted-decimal equivalent of /23. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 151.8.138.0/23
Network Address 151.8.138.0
Broadcast Address 151.8.139.255
Subnet Mask 255.255.254.0
Wildcard Mask 0.0.1.255
Prefix Length /23
IP Address Class Class B
Total IP Addresses 512
Usable Host Addresses 510
First Usable IP 151.8.138.1
Last Usable IP 151.8.139.254
Network (Hex) 0x97088A00
Broadcast (Hex) 0x97088BFF
Address Type Public / Globally Routable

Binary Representation

Network Address
10010111.00001000 10010111.00001000.10001010.00000000
Subnet Mask
11111111.11111111.11111110.00000000

The first 23 bits (1s in the mask) identify the network. The remaining 9 bits identify hosts within the network.

Split into Equal Subnets

Split 151.8.138.0/23 into 2 equal /24 subnets (254 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 151.8.138.0/24 151.8.138.0 151.8.138.1 151.8.138.254 151.8.138.255 254
2 151.8.139.0/24 151.8.139.0 151.8.139.1 151.8.139.254 151.8.139.255 254

/23 Subnet Reference

Total IPs 512
Usable Hosts 510
Subnet Mask 255.255.254.0
Wildcard 0.0.1.255
Full /23 reference →

Related Ranges

Parent /22 block 151.8.136.0/22 Sibling /23 block 151.8.136.0/23

Adjacent Prefix Sizes

/21 2,046 hosts /22 1,022 hosts /23 510 hosts /24 254 hosts /25 126 hosts

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