IPRangeExplorer

187.234.216.0/21

Public

Class B — /21 prefix — 2,046 usable hosts

Network Address
187.234.216.0
Broadcast Address
187.234.223.255
Subnet Mask
255.255.248.0
Usable Hosts
2,046
First Usable IP
187.234.216.1
Last Usable IP
187.234.223.254
Total IPs
2,048
Prefix Length
/21

Network address — the base address of the block (187.234.216.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 187.234.223.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 2,046 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 255.255.248.0 is the dotted-decimal equivalent of /21. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 187.234.216.0/21
Network Address 187.234.216.0
Broadcast Address 187.234.223.255
Subnet Mask 255.255.248.0
Wildcard Mask 0.0.7.255
Prefix Length /21
IP Address Class Class B
Total IP Addresses 2,048
Usable Host Addresses 2,046
First Usable IP 187.234.216.1
Last Usable IP 187.234.223.254
Network (Hex) 0xBBEAD800
Broadcast (Hex) 0xBBEADFFF
Address Type Public / Globally Routable

Binary Representation

Network Address
10111011.11101010 10111011.11101010.11011000.00000000
Subnet Mask
11111111.11111111.11111000.00000000

The first 21 bits (1s in the mask) identify the network. The remaining 11 bits identify hosts within the network.

Split into Equal Subnets

Split 187.234.216.0/21 into 2 equal /22 subnets (1,022 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 187.234.216.0/22 187.234.216.0 187.234.216.1 187.234.219.254 187.234.219.255 1,022
2 187.234.220.0/22 187.234.220.0 187.234.220.1 187.234.223.254 187.234.223.255 1,022

/21 Subnet Reference

Total IPs 2,048
Usable Hosts 2,046
Subnet Mask 255.255.248.0
Wildcard 0.0.7.255
Full /21 reference →

Related Ranges

Parent /20 block 187.234.208.0/20 Sibling /21 block 187.234.208.0/21

Adjacent Prefix Sizes

/19 8,190 hosts /20 4,094 hosts /21 2,046 hosts /22 1,022 hosts /23 510 hosts

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