pfsense_update_interface_gre · Pfsense MCP: Risk & Policy

WHAT IT DOES

What pfsense_update_interface_gre does on Pfsense

AI agents use pfsense_update_interface_gre to create or update resources in Pfsense — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Pfsense environment.

WHY IT NEEDS A POLICY

Why pfsense_update_interface_gre needs a policy

The 'update' prefix strongly implies this tool modifies an existing GRE (Generic Routing Encapsulation) tunnel interface configuration on a pfSense firewall. Changing network tunnel interfaces can disrupt network connectivity, expose or reroute traffic, and affect security posture. The description is empty, reducing confidence, but the naming convention is consistent with other Write-category tools on this server.

From the tool's definition Tool name: pfsense_update_interface_gre — 'update' suggests modification; 'interface_gre' refers to a GRE tunnel interface on a pfSense firewall

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pfsense_update_interface_gre Rate-limited

pfsense_update_interface_gre stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "pfsense_update_interface_gre": {
      "limits": [
        {
          "counter": "pfsense_update_interface_gre_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Pfsense, so you can run agents against it safely.

FAQ

Questions about pfsense_update_interface_gre

What does the pfsense_update_interface_gre tool do? +

pfsense_update_interface_gre. It is categorised as a Write tool in the Pfsense MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pfsense_update_interface_gre? +

Register the Pfsense MCP server in PolicyLayer and add a rule for pfsense_update_interface_gre: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Pfsense. Nothing to install.

What risk level is pfsense_update_interface_gre? +

pfsense_update_interface_gre is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit pfsense_update_interface_gre? +

Yes. Add a rate_limit block to the pfsense_update_interface_gre rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block pfsense_update_interface_gre completely? +

Set action: deny in the PolicyLayer policy for pfsense_update_interface_gre. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides pfsense_update_interface_gre? +

pfsense_update_interface_gre is provided by the Pfsense MCP server (abl030/pfsense-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.