18.64.0.0/23

Public

Class A — /23 prefix — 510 usable hosts

Network Address
18.64.0.0
Broadcast Address
18.64.1.255
Subnet Mask
255.255.254.0
Usable Hosts
510
First Usable IP
18.64.0.1
Last Usable IP
18.64.1.254
Total IPs
512
Prefix Length
/23

Network address — the base address of the block (18.64.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 18.64.1.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 510 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask255.255.254.0 is the dotted-decimal equivalent of /23. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 18.64.0.0/23
Network Address 18.64.0.0
Broadcast Address 18.64.1.255
Subnet Mask 255.255.254.0
Wildcard Mask 0.0.1.255
Prefix Length /23
IP Address Class Class A
Total IP Addresses 512
Usable Host Addresses 510
First Usable IP 18.64.0.1
Last Usable IP 18.64.1.254
Network (Hex) 0x12400000
Broadcast (Hex) 0x124001FF
Address Type Public / Globally Routable

Binary Representation

Network Address
00010010.01000000 00010010.01000000.00000000.00000000
Subnet Mask
11111111.11111111.11111110.00000000

The first 23 bits (1s in the mask) identify the network. The remaining 9 bits identify hosts within the network.

Split into Equal Subnets

Split 18.64.0.0/23 into 2 equal /24 subnets (254 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 18.64.0.0/24 18.64.0.0 18.64.0.1 18.64.0.254 18.64.0.255 254
2 18.64.1.0/24 18.64.1.0 18.64.1.1 18.64.1.254 18.64.1.255 254

/23 Subnet Reference

Total IPs 512
Usable Hosts 510
Subnet Mask 255.255.254.0
Wildcard 0.0.1.255

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