ADR-0002: No Host Firewall Rules in Initial Foundation
Status
Accepted
Context
The HomeOps Server Foundation Phase 1 focuses on establishing a clean, understandable, and rebuildable Proxmox VE base system.
At this stage, the primary objectives are:
- To validate basic host stability and management access
- To document baseline architectural and security decisions
- To avoid introducing configuration complexity before service roles are defined
While Proxmox VE provides integrated host-level firewall capabilities, effective firewall policy design depends on a clear understanding of:
- Exposed services
- Network segmentation
- Trust boundaries
- Operational access patterns
None of these are fully defined during the initial foundation phase.
Decision
No host-level firewall rules will be actively enforced on the Proxmox VE host during Phase 1 of the HomeOps Server Foundation.
The host will rely on:
- Default service exposure
- Network-level controls provided by the upstream router
- Limited and controlled management access
Firewall configuration is explicitly deferred until later phases, once service roles and network segmentation are introduced.
Consequences
Positive
- Reduced risk of accidental lockout during early setup
- Simpler troubleshooting and recovery
- Clear separation between foundation setup and security enforcement
- Firewall policies can be designed with full context later
Negative
- The host does not benefit from defense-in-depth at the host firewall layer during Phase 1
- Security relies more heavily on upstream network controls
Notes
This decision is not a statement against host-based firewalls.
It reflects a deliberate sequencing choice: firewall rules will be introduced only after the system architecture, access model, and service exposure are clearly defined and documented.