IPRangeExplorer

192.168.144.0/21

Private (RFC 1918) RFC 1918

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

Network Address
192.168.144.0
Broadcast Address
192.168.151.255
Subnet Mask
255.255.248.0
Usable Hosts
2,046
First Usable IP
192.168.144.1
Last Usable IP
192.168.151.254
Total IPs
2,048
Prefix Length
/21

Network address — the base address of the block (192.168.144.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 192.168.151.255 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 192.168.144.0/21
Network Address 192.168.144.0
Broadcast Address 192.168.151.255
Subnet Mask 255.255.248.0
Wildcard Mask 0.0.7.255
Prefix Length /21
IP Address Class Class C
Total IP Addresses 2,048
Usable Host Addresses 2,046
First Usable IP 192.168.144.1
Last Usable IP 192.168.151.254
Network (Hex) 0xC0A89000
Broadcast (Hex) 0xC0A897FF
Governing RFC RFC 1918
Address Type Private (RFC 1918)

Binary Representation

Network Address
11000000.10101000 11000000.10101000.10010000.00000000
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 192.168.144.0/21 into 2 equal /22 subnets (1,022 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 192.168.144.0/22 192.168.144.0 192.168.144.1 192.168.147.254 192.168.147.255 1,022
2 192.168.148.0/22 192.168.148.0 192.168.148.1 192.168.151.254 192.168.151.255 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 192.168.144.0/20 Sibling /21 block 192.168.152.0/21

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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