The network observer for your home

Your network. Your clarity. Your decision.

Your home network is a small data centre today: TVs, voice assistants, cameras, thermostats, consoles, phones, NAS, printers — dozens of devices talking to the internet around the clock. CERNIS PRO scans your network, watches its traffic, investigates anything unusual and explains every finding in plain language. And the decisive difference: everything stays on your machine — no cloud, no account, no subscription.

It shows and puts things in context — but does not judge. You decide.

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What makes CERNIS PRO special

Radically local

There is no CERNIS server, no cloud, no account, no telemetry. Every scan, all traffic, every history stays in a local database on your machine. Uninstall CERNIS and it is all gone — nothing sits “somewhere”.

Passive observation

Core functions such as capturing requested host names (SNI) or live monitoring only read along instead of generating traffic. The sensitive SNI data is deliberately never stored permanently in the first place.

Facts with their source

When CERNIS tells you who is behind an IP address, it shows the source for every detail — name, network operator, country, certificate. No black box that simply says “dangerous” or “safe”.

You define “unusual”

The analysis rules are yours: which ports count as critical, when a warning is raised, which rules are active. You can import your own port lists. CERNIS ships sensible defaults — but you have the final say.

Depth beneath the friendly surface

From the one-click scan to the topology graph and the CVE cross-check, through to the network-wide DNS guardian and the detailed FRITZ!Box read-out: the range spans from beginner to professional — without overwhelming the beginner.

Features in detail

Trust you can verify

CERNIS PRO is built so you can trust it without having to. There is no server the application talks to, no account, no telemetry. And because CERNIS PRO is open source under the GPL, you do not have to take our word for it — you can read the code yourself.