IPRangeExplorer

151.8.128.0/20

Public

Class B — /20 prefix — 4,094 usable hosts

Network Address
151.8.128.0
Broadcast Address
151.8.143.255
Subnet Mask
255.255.240.0
Usable Hosts
4,094
First Usable IP
151.8.128.1
Last Usable IP
151.8.143.254
Total IPs
4,096
Prefix Length
/20

Network address — the base address of the block (151.8.128.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 151.8.143.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 4,094 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.255.240.0 is the dotted-decimal equivalent of /20. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 151.8.128.0/20
Network Address 151.8.128.0
Broadcast Address 151.8.143.255
Subnet Mask 255.255.240.0
Wildcard Mask 0.0.15.255
Prefix Length /20
IP Address Class Class B
Total IP Addresses 4,096
Usable Host Addresses 4,094
First Usable IP 151.8.128.1
Last Usable IP 151.8.143.254
Network (Hex) 0x97088000
Broadcast (Hex) 0x97088FFF
Address Type Public / Globally Routable

Binary Representation

Network Address
10010111.00001000 10010111.00001000.10000000.00000000
Subnet Mask
11111111.11111111.11110000.00000000

The first 20 bits (1s in the mask) identify the network. The remaining 12 bits identify hosts within the network.

Split into Equal Subnets

Split 151.8.128.0/20 into 2 equal /21 subnets (2,046 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 151.8.128.0/21 151.8.128.0 151.8.128.1 151.8.135.254 151.8.135.255 2,046
2 151.8.136.0/21 151.8.136.0 151.8.136.1 151.8.143.254 151.8.143.255 2,046

/20 Subnet Reference

Total IPs 4,096
Usable Hosts 4,094
Subnet Mask 255.255.240.0
Wildcard 0.0.15.255
Full /20 reference →

Related Ranges

Parent /19 block 151.8.128.0/19 Sibling /20 block 151.8.144.0/20

Adjacent Prefix Sizes

/18 16,382 hosts /19 8,190 hosts /20 4,094 hosts /21 2,046 hosts /22 1,022 hosts

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