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IPv4 Subnet Calculator



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Encodes URL components, not entire URLs.


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IPv4 Address Converter


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Worked example and practical uses
Important limitations
Frequently asked questions
Is this tool free?
Yes. YARVICO provides this calculator without requiring an account.
Are the results always accurate?
Check the tool-specific limitations above. Verify important results against trusted independent references.
Do I need to install software?
No. This tool runs in a modern web browser.


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Home / IT & Cybersecurity Tools / IPv4 Subnet Calculator


NETWORKING TOOLKIT
IPv4 Subnet Calculator
Find your network address, broadcast address, subnet mask, wildcard mask and usable IP range. Free, fast and processed locally in your browser.


Calculate your subnet
Enter an IPv4 address and a CIDR prefix from /0 to /32.
Your address is calculated on this device. No IP lookup or server request is made.




What is an IPv4 subnet calculator?
An IPv4 subnet calculator determines the network boundaries of an IP address and CIDR prefix. It helps network administrators, cybersecurity analysts and students plan address ranges and check routing configurations.
How to use this calculator
  1. Enter an IPv4 address such as 192.168.1.100.
  2. Enter a prefix length such as 24.
  3. Select Calculate subnet to see the network, mask, broadcast and usable address range.
  4. Use Copy results to paste the output into your notes.
Worked example: 192.168.1.100/24
The /24 prefix means that 24 bits identify the network and 8 bits remain for addresses. The subnet mask is 255.255.255.0, the network is 192.168.1.0, and the broadcast address is 192.168.1.255. For an ordinary subnet, the usable range is 192.168.1.1 through 192.168.1.254, or 254 host addresses.
Frequently asked questions
What does /24 mean?
It specifies 24 network bits in a 32-bit IPv4 address. That leaves 256 total addresses, typically 254 usable host addresses.
What is a wildcard mask?
It is the bitwise inverse of the subnet mask. For /24, the wildcard mask is 0.0.0.255.
Why are /31 and /32 different?
A /31 is often used for point-to-point links under RFC 3021, with both addresses available as endpoints. A /32 represents one address, often used for host routes. These are not ordinary multi-host broadcast subnets.
Does this tool scan my network?
No. It performs mathematical calculations in your browser and does not probe or connect to any IP address.
Related networking tools
CIDR ConverterIPv4 Address ConverterAll YARVICO tools
Educational reference only. Verify addressing and routing decisions against your actual network design.








          

        

Wednesday, November 4, 2026


          

        









Hitachi Energy CoreTec Product Vulnerabilities: Critical OS Command Injecti












CISA has issued an advisory for critical vulnerabilities in Hitachi Energy CoreTec products. These flaws could allow attackers to compromise system confidentiality, integrity, and availability through remote command execution and privilege escalation.


    

  • OS Command Injection (CVE-2026-13162): Authenticated users with certain roles can execute arbitrary system commands with full device control via improper timezone configuration handling.
    • 

  • Dirty Frag (CVE-2026-43284): Local unprivileged users can escalate privileges to root by exploiting a Linux kernel vulnerability in the IPsec ESP subsystem.
    • 



Both vulnerabilities affect CoreTec5 versions up to 3.4.0 and CoreTec4 versions up to 3.4.0. The advisory specifies that updating to CoreTec5 version 5.0.0 resolves both issues.


Hitachi Energy has confirmed these vulnerabilities impact critical infrastructure in the energy sector globally. The company headquarters are located in Switzerland.


Recommended next steps: Update to CoreTec5 version 5.0.0 for all affected products. Organizations should also implement network segmentation and restrict remote access to control systems.


What remains unknown: The exact attack surface and exploitation methods for the Dirty Frag vulnerability in real-world environments are not fully detailed in this advisory.
Official source: Hitachi Energy CoreTec Product (2026-10-29T12:00:00.000Z). Yarvico provides independent educational analysis.








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