151.4.2.0/23

Public

Class B — /23 prefix — 510 usable hosts

Network Address

151.4.2.0

Broadcast Address

151.4.3.255

Subnet Mask

255.255.254.0

Usable Hosts

510

First Usable IP

151.4.2.1

Last Usable IP

151.4.3.254

Total IPs

512

Prefix Length

/23

Network address — the base address of the block (151.4.2.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 151.4.3.255 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	151.4.2.0/23
Network Address	151.4.2.0
Broadcast Address	151.4.3.255
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	151.4.2.1
Last Usable IP	151.4.3.254
Network (Hex)	0x97040200
Broadcast (Hex)	0x970403FF
Address Type	Public / Globally Routable

Binary Representation

Network Address

10010111.00000100 10010111.00000100.00000010.00000000

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 151.4.2.0/23 into 2 equal /24 subnets (254 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.4.2.0/24	151.4.2.0	151.4.2.1	151.4.2.254	151.4.2.255	254
2	151.4.3.0/24	151.4.3.0	151.4.3.1	151.4.3.254	151.4.3.255	254

Split 151.4.2.0/23 into 4 equal /25 subnets (126 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.4.2.0/25	151.4.2.0	151.4.2.1	151.4.2.126	151.4.2.127	126
2	151.4.2.128/25	151.4.2.128	151.4.2.129	151.4.2.254	151.4.2.255	126
3	151.4.3.0/25	151.4.3.0	151.4.3.1	151.4.3.126	151.4.3.127	126
4	151.4.3.128/25	151.4.3.128	151.4.3.129	151.4.3.254	151.4.3.255	126

Split 151.4.2.0/23 into 8 equal /26 subnets (62 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.4.2.0/26	151.4.2.0	151.4.2.1	151.4.2.62	151.4.2.63	62
2	151.4.2.64/26	151.4.2.64	151.4.2.65	151.4.2.126	151.4.2.127	62
3	151.4.2.128/26	151.4.2.128	151.4.2.129	151.4.2.190	151.4.2.191	62
4	151.4.2.192/26	151.4.2.192	151.4.2.193	151.4.2.254	151.4.2.255	62
5	151.4.3.0/26	151.4.3.0	151.4.3.1	151.4.3.62	151.4.3.63	62
6	151.4.3.64/26	151.4.3.64	151.4.3.65	151.4.3.126	151.4.3.127	62
7	151.4.3.128/26	151.4.3.128	151.4.3.129	151.4.3.190	151.4.3.191	62
8	151.4.3.192/26	151.4.3.192	151.4.3.193	151.4.3.254	151.4.3.255	62

Split 151.4.2.0/23 into 16 equal /27 subnets (30 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.4.2.0/27	151.4.2.0	151.4.2.1	151.4.2.30	151.4.2.31	30
2	151.4.2.32/27	151.4.2.32	151.4.2.33	151.4.2.62	151.4.2.63	30
3	151.4.2.64/27	151.4.2.64	151.4.2.65	151.4.2.94	151.4.2.95	30
4	151.4.2.96/27	151.4.2.96	151.4.2.97	151.4.2.126	151.4.2.127	30
5	151.4.2.128/27	151.4.2.128	151.4.2.129	151.4.2.158	151.4.2.159	30
6	151.4.2.160/27	151.4.2.160	151.4.2.161	151.4.2.190	151.4.2.191	30
7	151.4.2.192/27	151.4.2.192	151.4.2.193	151.4.2.222	151.4.2.223	30
8	151.4.2.224/27	151.4.2.224	151.4.2.225	151.4.2.254	151.4.2.255	30
9	151.4.3.0/27	151.4.3.0	151.4.3.1	151.4.3.30	151.4.3.31	30
10	151.4.3.32/27	151.4.3.32	151.4.3.33	151.4.3.62	151.4.3.63	30
11	151.4.3.64/27	151.4.3.64	151.4.3.65	151.4.3.94	151.4.3.95	30
12	151.4.3.96/27	151.4.3.96	151.4.3.97	151.4.3.126	151.4.3.127	30
13	151.4.3.128/27	151.4.3.128	151.4.3.129	151.4.3.158	151.4.3.159	30
14	151.4.3.160/27	151.4.3.160	151.4.3.161	151.4.3.190	151.4.3.191	30
15	151.4.3.192/27	151.4.3.192	151.4.3.193	151.4.3.222	151.4.3.223	30
16	151.4.3.224/27	151.4.3.224	151.4.3.225	151.4.3.254	151.4.3.255	30

/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 151.4.0.0/22 Sibling /23 block 151.4.0.0/23

Adjacent Prefix Sizes

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