Low Risk

gns3_list_nodes

List all nodes (devices) in a project.

How to control gns3_list_nodes ↓

What gns3_list_nodes does on GNS3 Network Simulator MCP Server

AI agents call gns3_list_nodes to retrieve information from GNS3 Network Simulator MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Low Risk

Why gns3_list_nodes needs a policy

This tool retrieves and queries existing data about network devices in a GNS3 project without creating, modifying, deleting, or executing anything. It is a read-only operation similar to 'list' or 'get' operations. The severity is low because misuse would only expose simulation metadata, not cause harm to the actual network simulation state.

From the tool's definition Tool name is 'gns3_list_nodes' and description states 'List all nodes (devices) in a project' — a purely informational operation with no modification or side effects.

Documented attack patterns abuse exactly the kind of access gns3_list_nodes gives an agent:

How to control gns3_list_nodes

PolicyLayer is an MCP gateway — it sits between your AI agents and GNS3 Network Simulator MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for gns3_list_nodes:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "gns3_list_nodes": {}
  }
}

gns3_list_nodes is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

  1. Create a free account and register GNS3 Network Simulator MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Questions about gns3_list_nodes

What does the gns3_list_nodes tool do? +

List all nodes (devices) in a project. It is categorised as a Read tool in the GNS3 Network Simulator MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on gns3_list_nodes? +

Register the GNS3 Network Simulator MCP Server MCP server in PolicyLayer and add a rule for gns3_list_nodes: 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 GNS3 Network Simulator MCP Server. Nothing to install.

What risk level is gns3_list_nodes? +

gns3_list_nodes is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit gns3_list_nodes? +

Yes. Add a rate_limit block to the gns3_list_nodes 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 gns3_list_nodes completely? +

Set action: deny in the PolicyLayer policy for gns3_list_nodes. 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 gns3_list_nodes? +

gns3_list_nodes is provided by the GNS3 Network Simulator MCP Server MCP server (wael-rd/gns3-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every GNS3 Network Simulator MCP Server tool call.

Start from GNS3 Network Simulator MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

42 GNS3 Network Simulator MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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