IPRangeExplorer

140.8.40.0/21

Public

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

Network Address
140.8.40.0
Broadcast Address
140.8.47.255
Subnet Mask
255.255.248.0
Usable Hosts
2,046
First Usable IP
140.8.40.1
Last Usable IP
140.8.47.254
Total IPs
2,048
Prefix Length
/21

Network address — the base address of the block (140.8.40.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 140.8.47.255 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 140.8.40.0/21
Network Address 140.8.40.0
Broadcast Address 140.8.47.255
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 140.8.40.1
Last Usable IP 140.8.47.254
Network (Hex) 0x8C082800
Broadcast (Hex) 0x8C082FFF
Address Type Public / Globally Routable

Binary Representation

Network Address
10001100.00001000 10001100.00001000.00101000.00000000
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 140.8.40.0/21 into 2 equal /22 subnets (1,022 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 140.8.40.0/22 140.8.40.0 140.8.40.1 140.8.43.254 140.8.43.255 1,022
2 140.8.44.0/22 140.8.44.0 140.8.44.1 140.8.47.254 140.8.47.255 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 140.8.32.0/20 Sibling /21 block 140.8.32.0/21

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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