156.4.2.128/25

Public

Class B — /25 prefix — 126 usable hosts

Network Address

156.4.2.128

Broadcast Address

156.4.2.255

Subnet Mask

255.255.255.128

Usable Hosts

126

First Usable IP

156.4.2.129

Last Usable IP

156.4.2.254

Total IPs

128

Prefix Length

/25

Network address — the base address of the block (156.4.2.128). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 156.4.2.255 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	156.4.2.128/25
Network Address	156.4.2.128
Broadcast Address	156.4.2.255
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	156.4.2.129
Last Usable IP	156.4.2.254
Network (Hex)	0x9C040280
Broadcast (Hex)	0x9C0402FF
Address Type	Public / Globally Routable

Binary Representation

Network Address

10011100.00000100.00000010 10011100.00000100.00000010.10000000

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 156.4.2.128/25 into 2 equal /26 subnets (62 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	156.4.2.128/26	156.4.2.128	156.4.2.129	156.4.2.190	156.4.2.191	62
2	156.4.2.192/26	156.4.2.192	156.4.2.193	156.4.2.254	156.4.2.255	62

Split 156.4.2.128/25 into 4 equal /27 subnets (30 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	156.4.2.128/27	156.4.2.128	156.4.2.129	156.4.2.158	156.4.2.159	30
2	156.4.2.160/27	156.4.2.160	156.4.2.161	156.4.2.190	156.4.2.191	30
3	156.4.2.192/27	156.4.2.192	156.4.2.193	156.4.2.222	156.4.2.223	30
4	156.4.2.224/27	156.4.2.224	156.4.2.225	156.4.2.254	156.4.2.255	30

Split 156.4.2.128/25 into 8 equal /28 subnets (14 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	156.4.2.128/28	156.4.2.128	156.4.2.129	156.4.2.142	156.4.2.143	14
2	156.4.2.144/28	156.4.2.144	156.4.2.145	156.4.2.158	156.4.2.159	14
3	156.4.2.160/28	156.4.2.160	156.4.2.161	156.4.2.174	156.4.2.175	14
4	156.4.2.176/28	156.4.2.176	156.4.2.177	156.4.2.190	156.4.2.191	14
5	156.4.2.192/28	156.4.2.192	156.4.2.193	156.4.2.206	156.4.2.207	14
6	156.4.2.208/28	156.4.2.208	156.4.2.209	156.4.2.222	156.4.2.223	14
7	156.4.2.224/28	156.4.2.224	156.4.2.225	156.4.2.238	156.4.2.239	14
8	156.4.2.240/28	156.4.2.240	156.4.2.241	156.4.2.254	156.4.2.255	14

Split 156.4.2.128/25 into 16 equal /29 subnets (6 usable hosts each).

#	CIDR	Network	First Usable	Last Usable	Broadcast	Hosts
1	156.4.2.128/29	156.4.2.128	156.4.2.129	156.4.2.134	156.4.2.135	6
2	156.4.2.136/29	156.4.2.136	156.4.2.137	156.4.2.142	156.4.2.143	6
3	156.4.2.144/29	156.4.2.144	156.4.2.145	156.4.2.150	156.4.2.151	6
4	156.4.2.152/29	156.4.2.152	156.4.2.153	156.4.2.158	156.4.2.159	6
5	156.4.2.160/29	156.4.2.160	156.4.2.161	156.4.2.166	156.4.2.167	6
6	156.4.2.168/29	156.4.2.168	156.4.2.169	156.4.2.174	156.4.2.175	6
7	156.4.2.176/29	156.4.2.176	156.4.2.177	156.4.2.182	156.4.2.183	6
8	156.4.2.184/29	156.4.2.184	156.4.2.185	156.4.2.190	156.4.2.191	6
9	156.4.2.192/29	156.4.2.192	156.4.2.193	156.4.2.198	156.4.2.199	6
10	156.4.2.200/29	156.4.2.200	156.4.2.201	156.4.2.206	156.4.2.207	6
11	156.4.2.208/29	156.4.2.208	156.4.2.209	156.4.2.214	156.4.2.215	6
12	156.4.2.216/29	156.4.2.216	156.4.2.217	156.4.2.222	156.4.2.223	6
13	156.4.2.224/29	156.4.2.224	156.4.2.225	156.4.2.230	156.4.2.231	6
14	156.4.2.232/29	156.4.2.232	156.4.2.233	156.4.2.238	156.4.2.239	6
15	156.4.2.240/29	156.4.2.240	156.4.2.241	156.4.2.246	156.4.2.247	6
16	156.4.2.248/29	156.4.2.248	156.4.2.249	156.4.2.254	156.4.2.255	6

IP Address Sample

Showing first 16 of 128 total IPs.

156.4.2.128 net

156.4.2.129

156.4.2.130

156.4.2.131

156.4.2.132

156.4.2.133

156.4.2.134

156.4.2.135

156.4.2.136

156.4.2.137

156.4.2.138

156.4.2.139

156.4.2.140

156.4.2.141

156.4.2.142

156.4.2.143

… 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 156.4.2.0/24 Sibling /25 block 156.4.2.0/25

Adjacent Prefix Sizes

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