47.128.0.0/17

Public

Class A — /17 prefix — 32,766 usable hosts

Network Address
47.128.0.0
Broadcast Address
47.128.127.255
Subnet Mask
255.255.128.0
Usable Hosts
32,766
First Usable IP
47.128.0.1
Last Usable IP
47.128.127.254
Total IPs
32,768
Prefix Length
/17

Network address — the base address of the block (47.128.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 47.128.127.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 32,766 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask255.255.128.0 is the dotted-decimal equivalent of /17. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 47.128.0.0/17
Network Address 47.128.0.0
Broadcast Address 47.128.127.255
Subnet Mask 255.255.128.0
Wildcard Mask 0.0.127.255
Prefix Length /17
IP Address Class Class A
Total IP Addresses 32,768
Usable Host Addresses 32,766
First Usable IP 47.128.0.1
Last Usable IP 47.128.127.254
Network (Hex) 0x2F800000
Broadcast (Hex) 0x2F807FFF
Address Type Public / Globally Routable

Binary Representation

Network Address
00101111.10000000 00101111.10000000.00000000.00000000
Subnet Mask
11111111.11111111.10000000.00000000

The first 17 bits (1s in the mask) identify the network. The remaining 15 bits identify hosts within the network.

Split into Equal Subnets

Split 47.128.0.0/17 into 2 equal /18 subnets (16,382 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 47.128.0.0/18 47.128.0.0 47.128.0.1 47.128.63.254 47.128.63.255 16,382
2 47.128.64.0/18 47.128.64.0 47.128.64.1 47.128.127.254 47.128.127.255 16,382

/17 Subnet Reference

Total IPs 32,768
Usable Hosts 32,766
Subnet Mask 255.255.128.0
Wildcard 0.0.127.255

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