Performance and side effects
What running a firewall costs you, what it can break, and how to tell NetSecWall apart from a real network fault.
A firewall is a thing you install that changes how your computer behaves. It's worth being straight about what that costs and what it can break, because the alternative is you discovering it later and blaming the wrong component.
What monitoring costs
Very little, by design. NetSecWall reads kernel events rather than sitting between your machine and the network. Your packets never pass through it, so it adds no latency to a connection and cannot slow a transfer. What it does use is a modest amount of CPU to process events and RAM to hold the live view, plus disk for the history database.
- CPU scales with connection churn, not bandwidth. A machine opening thousands of short connections costs more than one holding a saturated download.
- Disk grows with history retention. It's metadata, not contents, so it stays small — but it isn't zero, and the retention window is yours to set.
- Blocking costs essentially nothing extra. Enforcement happens inside the OS.
What it can break
Only blocking changes behavior. Everything below is a consequence of a rule you made:
| Symptom | Likely cause |
|---|---|
| An app hangs on startup | It's blocked and waiting on a network timeout it will never get |
| Windows Update stopped working | svchost.exe blocked wholesale — block the service, not the host process |
| A site loads with no images or styling | A country or category rule caught the CDN, not the site itself |
| Remote desktop dropped and won't reconnect | Block-everything was switched on, including your own way back in |
| An app worked yesterday, not today | Its update moved it to a new path, so an allow rule keyed to the old one no longer matches |
Living alongside other security software
Running two things that both manage the Windows Firewall is asking for rules that overwrite each other. The usual outcome is a block that mysteriously stops applying. If a suite already owns your firewall, use Companion mode or the packet-filter engine so NetSecWall enforces through its own path and leaves the other tool's rules alone.
Antivirus is a different matter. It scans files and NetSecWall watches the network, so the two don't overlap and both should be running.
VPNs, proxies, and virtual adapters
With a VPN active, connections are still attributed to the right program. The destination you see may be the VPN endpoint rather than the eventual server, though, and geolocation follows the tunnel. Country rules become much less meaningful — a country rule and a VPN together mostly produce confusion.
Virtual adapters from container runtimes and hypervisors carry real traffic from real processes, so WSL, Docker, and virtual machines all show up. That's correct, not a bug.
Battery and laptops
Steady-state monitoring is light, but it isn't free, and the background service means the machine does a little work whenever it's awake. On a laptop where every hour counts, running the app without the service is the cheaper configuration. You lose coverage while signed out, which is the trade.
Still stuck? Open a support ticket — we reply within one business day.