SEC.01
The playbook
The run starts read-only: the recon probes decide what happens next. The steps that follow are adapted to the distribution and state found — a real machine is rarely clean.
- 01recondoes a rule with the same name already exist?
- 02recondo other rules already cover this port?
- 03reconactive firewall profiles
- 04reconis a service actually listening on this port?
- 05actCreate the ruledestructiveverify
SEC.02
What it verifies
Each step ships its own check. The run only moves on when the check passes, so what the recipe reports as done is what is actually on the server.
- 01verifyCreate the ruleVerified by
Get-NetFirewallRule -DisplayName '${name}' | Get-NetFirewallPortFilter | Select-Object Protocol,LocalPort
SEC.03
Guardrails
Non-negotiable instructions the run must respect, whatever it finds on the server.
Open only the port strictly needed, restricted to an IP range if possible. Never disable the firewall and do not modify existing rules.
SEC.04
Variables
What you choose before launching — the recipe fills in the rest.
| Name | Meaning |
|---|---|
| ${name} | Rule name |
| ${port} | Port |
| ${protocol} | Protocol |
| ${remote_address} | Allowed source IP/range |
SEC.05
How a recipe runs in Servor
Servor is zero-knowledge: the platform cannot execute anything on its own. When you launch this recipe, a run reads the reconnaissance, plans the steps and asks for your approval. Each approved command is signed by your browser — with a key the server never sees — then relayed verbatim to the agent, which verifies the signature locally before executing.
search by intent — type “firewall”, get ufw
- 01Read-only reconnaissance before any change
- 02Every command signed by your browser, approved by you
- 03Each step verified before the run moves on, every run kept in the history
SEC.06
Deploy on Servor button
Maintain Firewall rule (Windows) or a project that needs it? Put this button in your README or on your site: one click and your users install it on their own server.
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Light background[](https://servor.app/deploy/new-firewall-rule-windows)SEC.07
More security recipes
- 01Harden SSHTurns off password login and root password login, keeps keys. Destructive: verify your key access first.
- 02fail2banfail2ban with the SSH jail on the right port, active and verified.
- 03UFW firewallUFW: denies incoming by default, allows the real SSH port + chosen ports, with a safety net. Destructive: keeps SSH open.
- 04Automatic security updatesEnables automatic security updates: unattended-upgrades (Debian/Ubuntu) or dnf-automatic (RHEL/Fedora).
- 05CrowdSecCrowdSec collaborative IPS, SSH collections and firewall bouncer.
Verified recipe
Run this recipe on your server
Connect a server, launch the recipe, and approve each step as Servor executes and verifies it. Free plan, no card required.