PortGuard: Keep Your Services Invisible to Scanners
PortGuard combines a modified fwknop-based server with a cross-platform client that supports the fwknop SPA protocol. Ports stay closed by default and open temporarily only after a valid AES/GPG-signed packet is verified.
Quick Server Install
Installs the latest open-source package built by GitHub Actions from the PortGuard server repository.
curl -fsSL https://portguard.net/install.sh | sudo bash
Traditional Exposure Mode (Risk)
- ✕Ports remain open all day and are continuously probed by global scanners.
- ✕Exposed services face brute-force attempts and exploit attacks directly.
- ✕Firewall allowlists become complex to maintain and lack dynamic flexibility.
PortGuard Mode (Solution)
- ✓Default Deny: Ports are completely invisible before authorization (stealth).
- ✓SPA Auth: Only specially formatted encrypted single packets can trigger access.
- ✓Dynamic Access: Temporarily allow only the source IP, then close automatically.
Core Features
Core Security Features
Strong defaults for teams that want SSH, admin panels, and private services to disappear until authorization is intentional.
Efficient SPA Communication
Send fwknop-compatible single-packet authorization without TCP handshake overhead, with strong stealth.
AES/GPG + HMAC
Integrated SHA256 integrity checks ensure commands are authentic and untampered.
Full Port Stealth
Default DROP behavior makes services appear unreachable to scanners.
Replay Attack Resistance
Time-window validation plus integrity checks quickly invalidates old packets.
Vegleiðing til havnaverju
A cleaner fwknop-compatible client for every device.
PortGuard Client supports the fwknop SPA protocol. Profiles, one-tap SPA, QR import, encrypted export, and activation stay compatible with fwknopd and PortGuard Server workflows.
How It Works
Security Workflow
PortGuard runs at the firewall edge of protected servers. It continuously inspects network traffic for authorization packets without exposing service handshakes externally.
Generate Authorization Packet
The client uses keys and a timestamp to generate an encrypted single packet.
Handshake-less Delivery
The packet is sent via UDP and similar methods, making handshake-based probing ineffective.
Dynamic Open
After validation, the server temporarily allows the source IP and then automatically removes the rule.
Use Cases
SSH Remote Operations
Protect port 22 and make it visible only briefly after an admin sends SPA.
Multi-Cloud Security
Unified access control across AWS/Azure and more to reduce exposure.
IoT Device Management
Protect IoT control interfaces and avoid direct public exposure.
ACL Automation
Combine scripts and rule cycles to automate temporary authorization.
Downloads and Installation
Supports multi-platform clients and server-side packages
Server Packages
Install PortGuard Server on Debian, Ubuntu, Rocky, CentOS, and OpenWrt
Use the quick installer for supported Linux servers, or download the latest package generated from the open-source GitHub Actions release pipeline.
Quick Install
One command server setup
curl -fsSL https://portguard.net/install.sh | sudo bash
The script detects the operating system, selects the matching package from the GitHub release manifest, verifies SHA256, installs dependencies, and leaves fwknopd ready for configuration export to PortGuard Client.
Open Source Release
Packages synced from GitHub
These packages are built automatically by GitHub Actions from the public PortGuard server source code.
| System | Version | Architecture | Package | Niðurtøka |
|---|---|---|---|---|
| Loading packages from GitHub release... | ||||
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What is the relationship between PortGuard and fwknop?
PortGuard is built around the fwknop SPA protocol. PortGuard Client is a cross-platform client that sends fwknop-compatible SPA packets, while PortGuard Server is a modified server based on the upstream fwknop project. Compared with traditional sequence-based port knocking, this single encrypted packet model is faster, stealthier, and resistant to replay attacks.
Kann eg gera ein profil og brúka eitt knock til at loyva einum ávísum IP at fáa atgongd til hvønn tænastuport?
Ja. Set ambætaraatgongdarstrofuna upp við OPEN_PORTS ANY og brúka ein kundaprofil við ACCESS ANY. Profilurin kann gerast og innflytast einaferð, síðani endurnýtast. Hvørt gyldugt banka skapar eina fyribils keldu-IP reglu, sum ger, at IP, sum ALLOW_IP velur, kann røkka øllum TCP og UDP tænastuportum, til FW_TIMEOUT gongur út. Eftir útgingin, send nýtt banka. Hetta er ein háttur við høgum privilegium: brúka stutta timeout, verja profilin og lyklarnar, og minst til, at uppstreymoyar skýggja brandveggir, beinareglur og tænastugóðkenning framvegis eru galdandi.
Wie schneidet fwknop im Vergleich zu tnock ab?
Beide sollen Netzwerkports verbergen, aber fwknop ist eine fortschrittlichere SPA-Lösung. tnock und ähnliche sequenzbasierte Daemons erkennen ein bestimmtes Verbindungsversuchsmuster über mehrere geschlossene Ports, was länger dauert und replay-anfällig ist. fwknop löst das durch ein einzelnes kryptografisch signiertes und zeitgestempeltes Payload. Vorteile: deutlich höhere Sicherheit, Schutz vor Replay und nahtlose Integration mit modernen Firewalls.
Wie mache ich meine Website oder meinen privaten Dienst nur für bestimmte Personen erreichbar?
By default, PortGuard Server, modified from fwknop, configures your server's firewall to block all inbound traffic to your service port. The service appears completely offline to the public. When an authorized user needs access, they use PortGuard Client with their unique cryptographic key to send a fwknop-compatible Single Packet Authorization (SPA) packet. Once verified, the server dynamically whitelists their current IP address for a brief period.
Wie stelle ich Sicherheit und Datenschutz eines öffentlich erreichbaren NAS ohne Datenleck sicher?
Ein NAS direkt ins Internet zu stellen ist wegen permanenter Botnet- und Scanner-Anfragen sehr riskant. Es gibt meist zwei sichere Wege:
- Option 1: Cloudflare Zero Trust (Tunnels) Hier wird NAS-Traffic über Cloudflare geleitet, ohne eingehende Ports zu öffnen. Vorteile: sehr einfach, keine öffentliche IP nötig, zusätzliche WAF-Schicht. Nachteile: Traffic läuft über Dritte, also Abhängigkeit von Cloudflares Datenschutz; Übertragungsraten sind im Free-Tier-Routing oft begrenzt und für große Medienstreams weniger ideal.
- Option 2: Eigene öffentliche IP + fwknop Port Knocking Sie öffnen einen Port am Router, schützen ihn aber mit fwknop (SPA). Der Port bleibt im öffentlichen Internet unsichtbar und öffnet nur bei einem gültigen kryptografisch signierten Zugriffspaket. Vorteile: volle Datenhoheit ohne Drittserver und maximale Hardware-Übertragungsrate dank Direktverbindung (gut für Video-Streaming). Nachteile: echte öffentliche IP und etwas technischere Ersteinrichtung erforderlich.
Verlangsamt fwknop PortGuard meine Verbindung, nachdem der Port geöffnet wurde?
No. The fwknop-compatible PortGuard Server only handles the initial authorization packet. Once the firewall rule is dynamically created and your IP is authorized, your connection via SSH, WireGuard, or directly to your NAS operates directly between your client and the server at full line speed.
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Official Contact
Need help with PortGuard?
For purchase recovery, activation issues, deployment questions, or security reports, contact the official PortGuard support mailbox.
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