local_ports

SERVERMcp Nettools SOURCEaaronckj/mcp-nettools

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/aaronckj-mcp-nettools/local-ports.md

WHAT IT DOES

What local_ports does on Mcp Nettools

AI agents call local_ports to retrieve information from Mcp Nettools without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why local_ports is rated Low

This tool only reads and reports network socket/port information from the local machine — no data is created, modified, or deleted. However, it reveals the system's network exposure (open ports and associated processes), which is sensitive reconnaissance information that could be misused to identify attack surfaces, hence medium severity.

From the tool's definition List listening TCP and UDP ports on the local machine... Uses ss (Linux) with fallback to netstat.

Risk signalsAdmin/system-level operation

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs local_ports safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Mcp Nettools, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For local_ports, this is the rule to start with:

local_ports Allowed

local_ports is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "local_ports": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Mcp Nettools, apply this rule, and every local_ports call is checked against it from then on.

FAQ

Questions about local_ports

What does the local_ports tool do? +

List listening TCP and UDP ports on the local machine. protocol: 'tcp', 'udp', or 'all'. show_processes: include process names (requires root on some systems; set to false to skip). Uses ss (Linux) with fallback to netstat. It is categorised as a Read tool in the Mcp Nettools MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on local_ports? +

Register the Mcp Nettools MCP server in PolicyLayer and add a rule for local_ports: 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 Mcp Nettools. Nothing to install.

What risk level is local_ports? +

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

Can I rate-limit local_ports? +

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

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

local_ports is provided by the Mcp Nettools MCP server (aaronckj/mcp-nettools). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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