About sudotools.dev

sudotools.dev is a free collection of everyday utilities for system administrators, network engineers and anyone who spends time in a terminal. The goal is simple: fast, no-nonsense tools that do one job well and get out of your way.

Privacy by design

Every tool on this site runs entirely in your browser. When you calculate a subnet, look up a MAC vendor, or generate a firewall config, the work happens locally on your device using client-side JavaScript. Your inputs — IP addresses, MAC addresses, firewall rules, server configs — are never sent to, logged by, or stored on any server we control. There is no account, no sign-up, and no login.

What you'll find here

• Subnet calculator — IPv4 network, broadcast, usable host range, host count and wildcard mask from an address plus mask or CIDR prefix.
• MAC vendor lookup — identify a device manufacturer from its MAC address using the public IEEE OUI registry, matched locally in your browser.
• iptables generator — a default-deny firewall skeleton with loopback, established/related, ICMP, NAT masquerade and port-forward rules, plus persistence guidance.
• ISC DHCP config generator — a dhcpd.conf with lease settings, subnets and static host reservations.
• nginx server block generator — static, reverse-proxy or PHP-FPM server blocks with SSL, HTTP→HTTPS redirect, Let's Encrypt paths, gzip and WebSocket support.

Who makes this

sudotools.dev is an independent project built and maintained by a working sysadmin, funded by unobtrusive advertising so the tools can stay free. New utilities are added over time based on what's genuinely useful day to day. If there's something you'd like to see, the contact page is the place to ask.

How it's funded

To keep the site free and online, sudotools.dev displays advertising (including Google AdSense). Ads never have access to what you type into the tools. See our privacy policy for details on cookies and how to opt out of personalised ads.

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