Results
Network IP
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Broadcast IP
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Subnet Mask
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CIDR Notation
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Valid IPs Per Subnet
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Number of Subnets
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IP Range
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Subnet Visualization
Network Address
Usable IP Range
Broadcast Address
Understanding CIDR
CIDR (Classless Inter-Domain Routing) is a method for allocating IP addresses and routing IP packets. It provides a more flexible and efficient way to assign IP address blocks compared to the traditional classful networking system.
In AWS Cloud Platform
In AWS VPC, we can reserve private IP addresses within a subnet to ensure they remain available for critical resources like databases or application servers. AWS automatically reserves five IP addresses in every subnet:
1. First IP -> Network Address
2. Second IP -> VPC Router
3. Third IP -> DNS Reserved Address
4. Fourth IP -> AWS Future use
5. Last IP -> Broadcast Address
Calculation Steps
- Determine the network bits from CIDR notation (/24 means 24 network bits)
- Calculate available hosts using 2^(32-CIDR) - 2
- Find network and broadcast addresses
- Determine the usable IP range
Example: 192.168.1.0/24
- Subnet Mask: 255.255.255.0
- Available Hosts: 254 (2^8 - 2)
- Network Address: 192.168.1.0
- Broadcast Address: 192.168.1.255
- Usable IP Range: 192.168.1.1 - 192.168.1.254