Perimeter
It tells you what changed on your network, and when it cannot tell.
Every network scanner hands you a table of addresses and open ports. Perimeter reads the table for you, and it is never allowed to call your network quiet while it cannot see.
In development2026Python · nmap · mDNS · SSDPperimeter.davidcvet.com
Example runs. The layout, remedies and verdicts are the tool's own.
Why
Silence is not the same as safety.
A tool that reports nothing new while it is actually blind is worse than no tool, because you would believe it. So every probe answers with one of five words, and two of them are never allowed to mean the same thing.
okRan, and saw something.
emptyRan cleanly and saw nothing. Ambiguous, and reported as ambiguous.
BLOCKEDFailed for a reason it can name, with the remedy beside it.
skippedNeeds privileges it does not have. Not a failure.
ERRORA bug, not a finding: the network is unknown, not clean.
The first real run
Its own first verdict was wrong, and the design caught it.
Every probe passed, and the verdict was a confident SEEING. But the sweep had found 2 hosts on a network where the ARP cache already knew 6. Now the collectors are checked against each other, and two of them disagreeing outranks either one passing on its own.
Roadmap
Built in epochs, each finished before the next is written.
- 0Can you even see?
- 1Inventory
- 1.5Amendments
- 2Identitynext
- 3Change
- 4The dispatch
- 5Linux
- 6Release
Nothing there, and I cannot see, are different answers.
No Python dependencies, and no MAC address ever leaves the machine.