IPRangeExplorer

0.0.0.0/0

Public

0.0.0.0/0 is the default route, representing all IPv4 addresses. In routing tables it is the "route of last resort." In security groups and firewall rules it means "allow all IPs" — use with caution.

Network Address
0.0.0.0
Broadcast Address
255.255.255.255
Subnet Mask
0.0.0.0
Usable Hosts
4,294,967,294
First Usable IP
0.0.0.1
Last Usable IP
255.255.255.254
Total IPs
4,294,967,296
Prefix Length
/0

Network address — the base address of the block (0.0.0.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 255.255.255.255 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 4,294,967,294 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask — 0.0.0.0 is the dotted-decimal equivalent of /0. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 0.0.0.0/0
Network Address 0.0.0.0
Broadcast Address 255.255.255.255
Subnet Mask 0.0.0.0
Wildcard Mask 255.255.255.255
Prefix Length /0
IP Address Class Class A
Total IP Addresses 4,294,967,296
Usable Host Addresses 4,294,967,294
First Usable IP 0.0.0.1
Last Usable IP 255.255.255.254
Network (Hex) 0x00000000
Broadcast (Hex) 0xFFFFFFFF
Address Type Public / Globally Routable

Binary Representation

Network Address
00000000.00000000.00000000.0000000 00000000.00000000.00000000.00000000
Subnet Mask
00000000.00000000.00000000.00000000

The first 0 bits (1s in the mask) identify the network. The remaining 32 bits identify hosts within the network.

Split into Equal Subnets

Split 0.0.0.0/0 into 2 equal /1 subnets (2,147,483,646 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 0.0.0.0/1 0.0.0.0 0.0.0.1 127.255.255.254 127.255.255.255 2,147,483,646
2 128.0.0.0/1 128.0.0.0 128.0.0.1 255.255.255.254 255.255.255.255 2,147,483,646

Common Use Cases

  • → Default gateway route (route of last resort)
  • → Security group rule meaning "allow all IPs"
  • → VPN split tunneling — force all traffic through VPN
  • → BGP route advertisement of a full routing table

/0 Subnet Reference

Total IPs 4,294,967,296
Usable Hosts 4,294,967,294
Subnet Mask 0.0.0.0
Wildcard 255.255.255.255
Full /0 reference →

Related Ranges

Adjacent Prefix Sizes

/0 4,294,967,294 hosts /1 2,147,483,646 hosts /2 1,073,741,822 hosts

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