> ## Documentation Index
> Fetch the complete documentation index at: https://docs.usenubis.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Cloud Firewalls

> Control inbound and outbound traffic for project resources with reusable firewall policies.

## Firewall model

Nubis firewalls let you define traffic rules once and attach them to the resources that need them. They are a core part of the project networking layer alongside VPCs, load balancers, floating IPs, and DNS.

## What you can do

* Create and delete project-scoped firewalls.
* Define inbound and outbound rules by protocol, port, and source or destination range.
* Attach or detach firewalls from virtual machines as your topology changes.
* Keep access policy separate from app deployment logic.

## Recommended workflow

<Steps>
  <Step title="Start from network intent">
    Define what should be reachable from the public internet, what should stay private, and which internal services need east-west access.
  </Step>

  <Step title="Create the firewall">
    Add only the rules needed for the workload to function, then attach it to the relevant instances.
  </Step>

  <Step title="Review after each topology change">
    Revisit firewall attachments and rules whenever you add new load balancers, databases, or public entry points.
  </Step>
</Steps>

## Good operating habits

* Keep public ingress narrow and explicit.
* Use separate firewalls for different workload classes instead of one oversized shared ruleset.
* Pair firewall review with DNS and load-balancer changes so exposure stays intentional.