203.0.113.0/25

Public RFC 5737

Class C — /25 prefix — 126 usable hosts

Network Address
203.0.113.0
Broadcast Address
203.0.113.127
Subnet Mask
255.255.255.128
Usable Hosts
126
First Usable IP
203.0.113.1
Last Usable IP
203.0.113.126
Total IPs
128
Prefix Length
/25

Network address — the base address of the block (203.0.113.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 203.0.113.127 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 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 203.0.113.0/25
Network Address 203.0.113.0
Broadcast Address 203.0.113.127
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 203.0.113.1
Last Usable IP 203.0.113.126
Network (Hex) 0xCB007100
Broadcast (Hex) 0xCB00717F
Governing RFC RFC 5737
Address Type Public / Globally Routable

Binary Representation

Network Address
11001011.00000000.01110001 11001011.00000000.01110001.00000000
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.

Subnet Breakdown — splitting into /26

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

CIDR Network Broadcast First Usable Last Usable Hosts
203.0.113.0/26 203.0.113.0 203.0.113.63 203.0.113.1 203.0.113.62 62
203.0.113.64/26 203.0.113.64 203.0.113.127 203.0.113.65 203.0.113.126 62

IP Address Sample

Showing first 16 of 128 total IPs.

203.0.113.0 net
203.0.113.1
203.0.113.2
203.0.113.3
203.0.113.4
203.0.113.5
203.0.113.6
203.0.113.7
203.0.113.8
203.0.113.9
203.0.113.10
203.0.113.11
203.0.113.12
203.0.113.13
203.0.113.14
203.0.113.15
… 112 more IPs …

/25 Subnet Reference

Total IPs 128
Usable Hosts 126
Subnet Mask 255.255.255.128
Wildcard 0.0.0.127

Calculate Another