port_scan
Check multiple TCP ports on a host. ports: comma-separated or ranges (e.g., '22,80,443,8000-8080'). Max 500 ports. timeout: 1-30 s. open_only: if True, omit closed ports from the 'ports' dict (useful for large ranges).
This record as markdown: /tools/aaronckj-mcp-nettools/port-scan.md
What port_scan does on Mcp Nettools
AI agents invoke port_scan to trigger actions in Mcp Nettools. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
Why port_scan is rated High
Port scanning actively probes a remote host by initiating TCP connections, which is an external network operation whose effects depend on arguments. This is not a passive read — it sends packets to potentially unauthorized targets. Misuse could trigger IDS/IPS alerts, violate network policies, or be used for reconnaissance against third-party systems, making it high severity.
From the tool's definition 'Check multiple TCP ports on a host' with 'comma-separated or ranges (e.g., 22,80,443,8000-8080). Max 500 ports.'
Attacks that exploit this kind of access
The rule that runs port_scan 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 port_scan, this is the rule to start with:
port_scan stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Mcp Nettools, apply this rule, and every port_scan call is checked against it from then on.
Questions about port_scan
Check multiple TCP ports on a host. ports: comma-separated or ranges (e.g., '22,80,443,8000-8080'). Max 500 ports. timeout: 1-30 s. open_only: if True, omit closed ports from the 'ports' dict (useful for large ranges). It is categorised as a Execute tool in the Mcp Nettools MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Mcp Nettools MCP server in PolicyLayer and add a rule for port_scan: 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.
port_scan is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the port_scan 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.
Set action: deny in the PolicyLayer policy for port_scan. 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.
port_scan 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.
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