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Networking Toolbox

The sysadmin's Swiss Army knife

Subnetting
CIDR
IP Tools
DNS Tools
Lookups
Ref

Networking Toolbox

Subnetting

  • IPv4 Subnet Calculator
  • IPv6 Subnet Calculator
  • VLSM Calculator
  • Supernet Calculator
  • Subnet Planner

CIDR Tools

CIDR Masks

  • CIDR → Mask
  • Mask → CIDR

Set Operations

  • Difference (A - B)
  • Overlap (A ∩ B)
  • Contains (A ⊆ B)

More

  • IP Range to CIDR
  • CIDR Summarizer
  • CIDR Split
  • Next Available Subnet
  • Free Space Finder
  • CIDR Deaggregate
  • CIDR Compare
  • CIDR Allocator
  • CIDR Alignment
  • Wildcard Mask Converter

IP Tools

Number Formats

  • Format Representations

Address Calculations

  • IP Distance Calculator
  • Nth IP Calculator
  • Random IP Generator
  • IP Regex Generator
  • IP Address Validator
  • IP Enumerate

IPv6 Notation

  • IPv6 Expand
  • IPv6 Compress
  • IPv6 Normalizer
  • IPv6 Zone ID Handler
  • IPv6 Solicited-Node
  • IPv6 Teredo Parser
  • IPv6 NAT64 Translator

IP Families

  • IPv4 → IPv6
  • IPv6 → IPv4

Address Generation

  • EUI-64 Converter
  • ULA Generator
  • MAC Address Converter

DNS

DNS Generators

  • PTR Generator

Reverse DNS

  • PTR Generator
  • Reverse Zone Generator
  • Reverse Zones Calculator
  • PTR Sweep Planner

Record Generators

  • A/AAAA Bulk Generator
  • CNAME Builder
  • MX Record Planner
  • SRV Record Builder
  • TXT Record Escape Tool
  • SPF Policy Builder
  • DKIM Key Generator
  • DMARC Policy Builder
  • CAA Record Builder
  • TLSA Generator
  • SSHFP Generator
  • SVCB/HTTPS Builder
  • NAPTR Builder
  • LOC Builder
  • RP Builder
  • IDN Punycode Converter

DNS Utilities

  • DNS Record Validator
  • TTL Calculator
  • EDNS Size Estimator
  • DNS Label Normalizer

Zone File Tools

  • Zone Linter
  • Zone Diff
  • Zone Statistics
  • Name Length Checker

DNSSEC Tools

  • DNSKEY Key Tag Calculator
  • DS Record Generator
  • NSEC3 Hash Calculator
  • CDS/CDNSKEY Builder
  • RRSIG Planner

Diagnostics

DNS Diagnostics

  • DNS Lookup
  • Reverse DNS Lookup
  • DNS Propagation Checker
  • SPF Record Evaluator
  • DMARC Policy Checker
  • CAA Effective Policy
  • NS/SOA Consistency Check
  • DNSSEC AD Flag Checker
  • DNSSEC Validation Chain
  • DNS Blacklist Checker
  • AXFR Security Tester
  • DNS Query Performance
  • SOA Serial Analyzer
  • DNS Trace
  • Glue Check
  • SPF Flatten

HTTP Diagnostics

  • HTTP Headers Analyzer
  • Redirect Trace
  • Security Headers Analyzer
  • CORS Policy Checker
  • HTTP Performance Analyzer
  • HTTP Compression Check
  • Cookie Security Inspector

TLS Diagnostics

  • TLS Certificate Analyzer
  • TLS Versions Probe
  • TLS ALPN Negotiation
  • OCSP Stapling
  • Cipher Presets
  • Service Banner Grabber
  • TLS Handshake Analyzer
  • CT Log Search

Network Diagnostics

  • TCP Port Checker
  • HTTP Ping
  • BGP Route Lookup
  • IPv6 Connectivity Checker
  • ASN & Geolocation Lookup

Email Diagnostics

  • MX Health Checker
  • SPF Policy Checker
  • DMARC Policy Checker
  • SMTP TLS Checker
  • Greylisting Tester

RDAP Diagnostics

  • Domain RDAP Lookup
  • IP Address RDAP Lookup
  • ASN RDAP Lookup

Reference

Fundamentals

  • CIDR Notation Explained
  • VLSM in Plain English
  • Route Summarization / Supernetting

IPv6 Addressing

  • IPv6 Address Types & Key Prefixes
  • Common IPv6 Prefix Lengths
  • IPv4 in IPv6
  • IPv6 Privacy Addresses

Special Addresses

  • Common Subnet Sizes
  • Network Classes (A/B/C)
  • Reserved IP Ranges
  • Special-Use IPv4 Blocks (RFC 6890)
  • Private vs Public IP Addresses
  • Carrier-Grade NAT Explained
  • Link-Local & APIPA Addresses
  • IPv4 & IPv6 Multicast Basics

DNS & Protocols

  • Reverse DNS (PTR Records)
  • Reverse Zones for CIDR Delegation
  • ICMP & ICMPv6: Common Types
  • ARP vs NDP

Network Operations

  • What is an ASN?
  • Common TCP/UDP Ports
  • ACL Wildcard Masks
  • Common MTU/MSS Values
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Networking Toolbox is licensed under MIT © Alicia Sykes 2025

License

Networking Toolbox is licensed under the MIT License © Alicia Sykes 2025

Conditions

  • You Can
    • Use commercially
    • Modify the code
    • Distribute the code
    • Sublicense the app
  • You Cannot
    • Hold the author liable
  • You Must
    • Include the original copyright
    • Include the below license in full

Full License

Copyright (c) 2025 Alicia Sykes [aliciasykes.com]

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in the
Software without restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Networking Toolbox is licensed under MIT, (C) Alicia Sykes 2025

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