255.20.30.0/25

Public

Class E (Reserved) — /25 prefix — 126 usable hosts

Network Address
255.20.30.0
Broadcast Address
255.20.30.127
Subnet Mask
255.255.255.128
Usable Hosts
126
First Usable IP
255.20.30.1
Last Usable IP
255.20.30.126
Total IPs
128
Prefix Length
/25

Network address — the base address of the block (255.20.30.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 255.20.30.127 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 255.20.30.0/25
Network Address 255.20.30.0
Broadcast Address 255.20.30.127
Subnet Mask 255.255.255.128
Wildcard Mask 0.0.0.127
Prefix Length /25
IP Address Class Class E (Reserved)
Total IP Addresses 128
Usable Host Addresses 126
First Usable IP 255.20.30.1
Last Usable IP 255.20.30.126
Network (Hex) 0xFF141E00
Broadcast (Hex) 0xFF141E7F
Address Type Public / Globally Routable

Binary Representation

Network Address
11111111.00010100.00011110 11111111.00010100.00011110.00000000
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 255.20.30.0/25 into 2 equal /26 subnets (62 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 255.20.30.0/26 255.20.30.0 255.20.30.1 255.20.30.62 255.20.30.63 62
2 255.20.30.64/26 255.20.30.64 255.20.30.65 255.20.30.126 255.20.30.127 62

IP Address Sample

Showing first 16 of 128 total IPs.

255.20.30.0 net
255.20.30.1
255.20.30.2
255.20.30.3
255.20.30.4
255.20.30.5
255.20.30.6
255.20.30.7
255.20.30.8
255.20.30.9
255.20.30.10
255.20.30.11
255.20.30.12
255.20.30.13
255.20.30.14
255.20.30.15
… 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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