SimpleWall: The No-Bloat Firewall That Just Says “Yes” or “No”
There’s something refreshing about software that doesn’t try to be clever. SimpleWall isn’t a full endpoint security suite. It doesn’t scan files or run in the cloud. What it does — and does well — is give administrators a dead-simple way to say which apps are allowed to talk to the network… and which aren’t.
It hooks into Windows Filtering Platform (WFP), so it operates at a system level, but without introducing extra drivers or third-party engines. No background services. No telemetry. Just plain, readable rules and a “block by default” philosophy.
For locked-down environments or systems that must behave predictably, this tool often becomes indispensable.
Why It’s Still a Favorite Among Purists
| Feature | What That Means in Practice |
| WFP-Based Filtering | Uses native Windows filtering — no kernel tricks |
| Block-by-Default Mode | Only allows apps that are explicitly approved |
| Per-Executable Rules | Control by filename, not just by port or IP |
| Notifications for New Apps | Pop-up alert when something tries to connect for the first time |
| Logging and Filtering | See what’s been blocked or allowed, and by what rule |
| No Background Service | Runs only when the UI is open — ideal for lightweight setups |
| Open Source | Code is available for audit — important in security environments |
| Portable Version Available | No installation needed — runs clean from USB |
Where It Fits
SimpleWall tends to get deployed in situations where full-featured firewalls are overkill — or, ironically, too invasive. Test rigs, analysis machines, embedded systems, lab networks — anywhere admins need to know what leaves the machine and want to approve it first.
Also common:
– Developer workstations where strict outbound control is needed
– Machines with legacy or sensitive apps that can’t tolerate AV/firewall interference
– Minimalist Windows installations or VM snapshots used for forensic work
– Systems air-gapped from the internet but still communicating locally
It’s not designed to manage a fleet — no remote panel, no central logging — but for single-host lockdowns, it works better than expected.
Quick Setup Steps
1. Download from the official GitHub
→ https://www.henrypp.org/product/simplewall
2. Run the installer or unzip the portable version
3. Enable WFP filtering — this activates rule enforcement
4. Choose “block all except allowed” mode (recommended)
5. Start whitelisting needed applications:
– Either on first connection prompt
– Or manually from the rules list
6. Monitor logs to fine-tune behavior
Tips for Admins
– Rules are stored in a readable config file — easy to version or replicate
– Notifications can be noisy at first — disable after initial setup if needed
– Ideal for gold image prep: whitelist only approved tools before sealing
– Great for isolating rogue connections in mixed-trust environments
Final Thought
SimpleWall is what happens when a tool is built with one goal in mind — and then leaves everything else out. It doesn’t pretend to protect from malware, and it doesn’t make policy decisions. It just asks one thing: should this program connect to the network, yes or no?
And in many setups — that’s exactly the kind of clarity an admin needs.
