151.8.31.0/25

Public

Class B — /25 prefix — 126 usable hosts

Network Address

151.8.31.0

Broadcast Address

151.8.31.127

Subnet Mask

255.255.255.128

Usable Hosts

126

First Usable IP

151.8.31.1

Last Usable IP

151.8.31.126

Total IPs

128

Prefix Length

/25

Network address — the base address of the block (151.8.31.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 151.8.31.127 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 126 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.255.255.128 is the dotted-decimal equivalent of /25. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation	151.8.31.0/25
Network Address	151.8.31.0
Broadcast Address	151.8.31.127
Subnet Mask	255.255.255.128
Wildcard Mask	0.0.0.127
Prefix Length	/25
IP Address Class	Class B
Total IP Addresses	128
Usable Host Addresses	126
First Usable IP	151.8.31.1
Last Usable IP	151.8.31.126
Network (Hex)	0x97081F00
Broadcast (Hex)	0x97081F7F
Address Type	Public / Globally Routable

Binary Representation

Network Address

10010111.00001000.00011111 10010111.00001000.00011111.00000000

Subnet Mask

11111111.11111111.11111111.10000000

The first 25 bits (1s in the mask) identify the network. The remaining 7 bits identify hosts within the network.

Split into Equal Subnets

Split 151.8.31.0/25 into 2 equal /26 subnets (62 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.8.31.0/26	151.8.31.0	151.8.31.1	151.8.31.62	151.8.31.63	62
2	151.8.31.64/26	151.8.31.64	151.8.31.65	151.8.31.126	151.8.31.127	62

Split 151.8.31.0/25 into 4 equal /27 subnets (30 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.8.31.0/27	151.8.31.0	151.8.31.1	151.8.31.30	151.8.31.31	30
2	151.8.31.32/27	151.8.31.32	151.8.31.33	151.8.31.62	151.8.31.63	30
3	151.8.31.64/27	151.8.31.64	151.8.31.65	151.8.31.94	151.8.31.95	30
4	151.8.31.96/27	151.8.31.96	151.8.31.97	151.8.31.126	151.8.31.127	30

Split 151.8.31.0/25 into 8 equal /28 subnets (14 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.8.31.0/28	151.8.31.0	151.8.31.1	151.8.31.14	151.8.31.15	14
2	151.8.31.16/28	151.8.31.16	151.8.31.17	151.8.31.30	151.8.31.31	14
3	151.8.31.32/28	151.8.31.32	151.8.31.33	151.8.31.46	151.8.31.47	14
4	151.8.31.48/28	151.8.31.48	151.8.31.49	151.8.31.62	151.8.31.63	14
5	151.8.31.64/28	151.8.31.64	151.8.31.65	151.8.31.78	151.8.31.79	14
6	151.8.31.80/28	151.8.31.80	151.8.31.81	151.8.31.94	151.8.31.95	14
7	151.8.31.96/28	151.8.31.96	151.8.31.97	151.8.31.110	151.8.31.111	14
8	151.8.31.112/28	151.8.31.112	151.8.31.113	151.8.31.126	151.8.31.127	14

Split 151.8.31.0/25 into 16 equal /29 subnets (6 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	151.8.31.0/29	151.8.31.0	151.8.31.1	151.8.31.6	151.8.31.7	6
2	151.8.31.8/29	151.8.31.8	151.8.31.9	151.8.31.14	151.8.31.15	6
3	151.8.31.16/29	151.8.31.16	151.8.31.17	151.8.31.22	151.8.31.23	6
4	151.8.31.24/29	151.8.31.24	151.8.31.25	151.8.31.30	151.8.31.31	6
5	151.8.31.32/29	151.8.31.32	151.8.31.33	151.8.31.38	151.8.31.39	6
6	151.8.31.40/29	151.8.31.40	151.8.31.41	151.8.31.46	151.8.31.47	6
7	151.8.31.48/29	151.8.31.48	151.8.31.49	151.8.31.54	151.8.31.55	6
8	151.8.31.56/29	151.8.31.56	151.8.31.57	151.8.31.62	151.8.31.63	6
9	151.8.31.64/29	151.8.31.64	151.8.31.65	151.8.31.70	151.8.31.71	6
10	151.8.31.72/29	151.8.31.72	151.8.31.73	151.8.31.78	151.8.31.79	6
11	151.8.31.80/29	151.8.31.80	151.8.31.81	151.8.31.86	151.8.31.87	6
12	151.8.31.88/29	151.8.31.88	151.8.31.89	151.8.31.94	151.8.31.95	6
13	151.8.31.96/29	151.8.31.96	151.8.31.97	151.8.31.102	151.8.31.103	6
14	151.8.31.104/29	151.8.31.104	151.8.31.105	151.8.31.110	151.8.31.111	6
15	151.8.31.112/29	151.8.31.112	151.8.31.113	151.8.31.118	151.8.31.119	6
16	151.8.31.120/29	151.8.31.120	151.8.31.121	151.8.31.126	151.8.31.127	6

IP Address Sample

Showing first 16 of 128 total IPs.

151.8.31.0 net

151.8.31.1

151.8.31.2

151.8.31.3

151.8.31.4

151.8.31.5

151.8.31.6

151.8.31.7

151.8.31.8

151.8.31.9

151.8.31.10

151.8.31.11

151.8.31.12

151.8.31.13

151.8.31.14

151.8.31.15

… 112 more IPs …

/25 Subnet Reference

Total IPs 128

Usable Hosts 126

Subnet Mask 255.255.255.128

Wildcard 0.0.0.127

Full /25 reference →

Related Ranges

Parent /24 block 151.8.31.0/24 Sibling /25 block 151.8.31.128/25

Adjacent Prefix Sizes

/23 510 hosts /24 254 hosts /25 126 hosts /26 62 hosts /27 30 hosts