About
NetDash Toolkit
48 network engineering utilities in one static site: subnetting, addressing, config generation, diagnostics, reference tables and a handful of everyday developer tools. There is no backend. 36 of the 48 tools run offline and never leave your browser, and the remaining 12 name the host they contact before they send anything.
Subnet math, VLSM planning, address conversion, config generation, encoding, hashing and every reference table run on the values you type and nothing else. No request is made until you press a button. The site itself records page views through Vercel Analytics, which sees the URL you visited and never the contents of a tool.
| Tool | Contacts |
|---|---|
| IP Conflict Checker | not declared |
| Network Tester | the URL you enter, cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com |
| DNS Tools | cloudflare-dns.com, dns.google, dns.quad9.net, doh.opendns.com, dns.adguard-dns.com |
| Ping & Traceroute | the host you enter |
| Port Scanner | the host you enter |
| SSL/TLS Checker | the hostname you enter, api.certspotter.com |
| WHOIS Lookup | rdap.org, the registry or RIR RDAP server rdap.org redirects to |
| Email Diagnostics | cloudflare-dns.com, dns.google |
| OUI Lookup | api.maclookup.app |
| HTTP Headers Analyzer | api.hackertarget.com |
| Security Headers Checker | api.hackertarget.com, observatory-api.mdn.mozilla.net |
| Redirect Checker | api.hackertarget.com |
What leaves your device in the docs breaks the same list down by capability, names who operates each host, and says what it receives.
Next.js App Router exported as static HTML. Every tool is its own lazily loaded chunk, so opening one tool does not download the other 47. State that belongs in a link lives in the URL, so a calculation can be shared by copying the address bar.
Projects are stored in your browser. Cloud sync is opt-in and does nothing until you sign in, so the default install talks to no account service at all.
The same code ships as an Electron desktop app, which adds the operations a browser is not permitted to perform at all.
- IP Conflict Checkerreading the local ARP cache
- Network Testerreal ICMP ping
- DNS Toolsdirect DNS queries
- Ping & Traceroutereal ICMP ping, system traceroute, local network interface enumeration
- Port Scannerreal TCP connect scanning
In the browser, the ping tool measures an HTTPS round trip. That is a useful reachability signal, but it is not ICMP and the tool says so.
Builds are ad-hoc signed rather than notarized, so macOS asks before opening one. The release notes carry SHA-256 checksums and build provenance if you want to check what you downloaded.
IPv4 subnet math
Network = IP & Mask, Broadcast = Network | ~Mask, on unsigned 32-bit values so the high octet cannot overflow into a negative.
VLSM allocation
Sort subnets by host count descending, pick the prefix p where 2^(32-p)-2 >= hosts, then place each block on its own binary boundary.
IPv6 compression
RFC 5952: drop leading zeros per group, then replace the single longest run of zero groups with :: exactly once.
Conflict detection
Parses ARP tables, DHCP leases and MAC tables, correlates addresses across sources, and reports the evidence rather than a verdict.
All 48 tools are mounted in CI and run through axe-core against the full 2.2 AA rule set on every commit. Colour contrast is asserted separately, straight from the design tokens, because an automated checker cannot measure a page that never painted.
Automated checks cover roughly a third of the success criteria. The rest, focus order, meaningful sequence and sensible labels, are reviewed by hand. Every interactive target is at least 24 by 24 CSS pixels, and the interface is usable from 320 pixels wide.