Tools

Quick helpers for IPs, ports, and layers.

These little utilities are here to answer the kinds of questions I get from teammates and customers all the time: “what does this subnet mean?”, “is this port normal?”, and how everything lines up in the OSI model.

Network & security helpers

Most tools on this page run purely in your browser. No data is sent anywhere — it's just JavaScript doing math and lookups.

A few tools (public IP, MAC vendor lookup, and speed test) do make a clearly-labeled request to a third-party endpoint, because that data doesn't exist locally.

Loading tools JavaScript…

Pomodoro timer

A simple focus timer with quick presets (10–60 minutes). Runs locally in your browser.

25:00
Choose a length and press Start.

What's my IP?

Fetches your public IP as seen by the internet. This makes a single request to api.ipify.org.

Click “Get my public IP”.

Internet speed test (quick)

A fast, lightweight download test using Cloudflare's public speed endpoint (speed.cloudflare.com). Use this for a quick read; for a full test, open Cloudflare's speed page.

Open Cloudflare speed test
Click “Run download test”.

World timezone converter

Convert a time between time zones. This runs locally using your browser’s built-in Intl time zone data (no third-party requests).

Pick a time and zones. It auto-converts as you type.

Uses today in the “From” zone (DST-aware). If the conversion crosses midnight, you’ll see a +1 / -1 day indicator.

MAC lookup (vendor / OUI)

Enter a MAC address to look up the manufacturer (OUI). This sends the MAC you enter to api.macvendors.com.

Enter a MAC address above (any common format is fine).

“Why is this port open?”

Pick a common port to see what it's usually used for and how I think about securing it on a firewall or edge device.

Select a port to see details.

OSI layers

Click a layer to see how I think about it from a cybersecurity and CISO perspective.

Select a layer to see details.

Subnet helper

Type an IPv4 CIDR (for example 10.0.5.0/24) to see the network, broadcast, mask, and usable host range.

Enter a CIDR above to calculate details.

Common commands (Linux + Windows)

A quick copy/paste reference for the commands I reach for during networking and incident response.

Linux
ip a

Show interfaces and IP addresses.

ip r

Show the routing table.

ss -tulpn

List listening TCP/UDP ports with process names.

sudo lsof -i :443

Find what's bound to a specific port.

dig example.com

Query DNS and inspect answers.

curl -I https://example.com

Fetch HTTP headers (quick reachability + TLS sanity check).

ping -c 4 8.8.8.8

Basic connectivity + latency snapshot.

traceroute 8.8.8.8

See hop-by-hop path to a destination.

sudo tail -f /var/log/syslog

Follow logs live (path varies by distro).

sudo journalctl -u ssh --since today

Systemd journal: service-focused log view.

nslookup example.com

Legacy DNS query tool (handy when dig isn't installed).

sudo tcpdump -i any -nn port 53

Quick packet capture for DNS (change port/host as needed).

sudo systemctl status <service>

Check a service status (replace <service>).

sudo systemctl restart <service>

Restart a service after config changes.

df -h

Disk usage by filesystem.

free -h

Memory usage snapshot.

sudo ufw status verbose

Show UFW firewall rules (Ubuntu/Debian).

sudo nft list ruleset

Inspect nftables rules (modern Linux firewall).

sudo tail -n 200 /var/log/auth.log

Recent auth events (Debian/Ubuntu path).

Windows (PowerShell / CMD)
ipconfig /all

Show full interface config (IP, gateway, DNS, MAC).

Get-NetIPConfiguration

PowerShell view of IP/DNS/gateway info.

Resolve-DnsName example.com

DNS query from PowerShell.

Test-NetConnection example.com -Port 443

Connectivity + TCP port check (great for triage).

netstat -ano

Show connections + listening ports with PIDs.

Get-Process -Id <PID>

Map a PID back to a process (use with netstat output).

tracert 8.8.8.8

Windows traceroute equivalent.

whoami

Show your current user context (helps with permissions debugging).

arp -a

View ARP cache (who your host thinks is on the LAN).

route print

Show the routing table (Windows equivalent of ip r).

ipconfig /flushdns

Clear DNS resolver cache (good after DNS changes).

Get-NetTCPConnection -State Listen | Select LocalAddress,LocalPort,OwningProcess

PowerShell-friendly way to list listening ports and owning PIDs.

Get-WinEvent -LogName Security -MaxEvents 50

Pull recent security events (useful for IR triage).

Invoke-WebRequest https://example.com -Method Head

Quick HTTP HEAD request (similar to curl -I).

winget upgrade --all

Bulk update installed apps (if Winget is available).

sfc /scannow

System file integrity check (run as admin if needed).

Tip: use the filter to quickly find commands, then hit Copy.

Crypto cheat: quick hashes

Generate MD5, SHA-1, or SHA-256 for a string or IOC. This is for integrity checks and quick lookups — not for password storage.

Choose an algorithm and generate a hash — all in your browser.

Scratchpad

A dead-simple notepad that autosaves to your browser (local-only). Great for jotting an IP, ticket number, or notes mid-call.

Autosaves locally as you type.

Decision spinner

Stuck in “waiting mode”? Set a number of choices, optionally label them, and let the spinner pick one at random.

Set a count, optionally label choices, then spin.

Eisenhower matrix

A 2×2 prioritization board (urgent vs. important). Add tasks into a quadrant and check them off. Saved locally in your browser.

Today's priorities

1) Do

Urgent + important

    2) Schedule

    Not urgent + important

      3) Delegate

      Urgent + not important

        4) Delete

        Not urgent + not important
          Add your first task — it will stay here (local-only) until you clear it.

          Fortinet heat map

          Live threat-map view from FortiGuard Labs. This embed is intentionally full-width and large so it’s useful as a “status board” at a glance.