192.168.1.128/25

Private (RFC 1918) RFC 1918

Class C — /25 prefix — 126 usable hosts

Network Address
192.168.1.128
Broadcast Address
192.168.1.255
Subnet Mask
255.255.255.128
Usable Hosts
126
First Usable IP
192.168.1.129
Last Usable IP
192.168.1.254
Total IPs
128
Prefix Length
/25

Network address — the base address of the block (192.168.1.128). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 192.168.1.255 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 mask255.255.255.128 is the dotted-decimal equivalent of /25. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 192.168.1.128/25
Network Address 192.168.1.128
Broadcast Address 192.168.1.255
Subnet Mask 255.255.255.128
Wildcard Mask 0.0.0.127
Prefix Length /25
IP Address Class Class C
Total IP Addresses 128
Usable Host Addresses 126
First Usable IP 192.168.1.129
Last Usable IP 192.168.1.254
Network (Hex) 0xC0A80180
Broadcast (Hex) 0xC0A801FF
Governing RFC RFC 1918
Address Type Private (RFC 1918)

Binary Representation

Network Address
11000000.10101000.00000001 11000000.10101000.00000001.10000000
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.

Subnet Breakdown — splitting into /26

This /25 block can be divided into 2 /26 subnets.

CIDR Network Broadcast First Usable Last Usable Hosts
192.168.1.128/26 192.168.1.128 192.168.1.191 192.168.1.129 192.168.1.190 62
192.168.1.192/26 192.168.1.192 192.168.1.255 192.168.1.193 192.168.1.254 62

IP Address Sample

Showing first 16 of 128 total IPs.

192.168.1.128 net
192.168.1.129
192.168.1.130
192.168.1.131
192.168.1.132
192.168.1.133
192.168.1.134
192.168.1.135
192.168.1.136
192.168.1.137
192.168.1.138
192.168.1.139
192.168.1.140
192.168.1.141
192.168.1.142
192.168.1.143
… 112 more IPs …

/25 Subnet Reference

Total IPs 128
Usable Hosts 126
Subnet Mask 255.255.255.128
Wildcard 0.0.0.127

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