whatismynetip

io.github.labaccessnowPublished by GitHub account labaccessnowv0.1.0Updated Oct 25, 2026

Subnet math, port and MAC lookups, DNS, DNSBL, TLS cert inspection, public IP. No account.

VerifiedSTDIODesktop onlyCloud & InfrastructureSecurity & Monitoring

Overview

AI-generated overview

A local MCP server that gives an assistant network utilities: subnet math, IP conversion, MAC vendor and port lookups, DNS and blocklist checks, TLS certificate

What you can do
Calculate subnets and test whether an address falls inside a block, for IPv4 and IPv6, and convert or normalize IP addresses and IPv6 forms offline from bundled data. Look up MAC vendors from a bundled IEEE table and identify what runs on a port, with exposure guidance, by number or service search. Resolve DNS records and reverse DNS over DNS-over-HTTPS, and check addresses against common blocklists. Inspect the TLS certificate a host serves, including expiry, SANs, chain verification, protocol and cipher. Report the public IP the internet sees, with edge location, ASN, reverse DNS and a datacenter or VPN hint.
When to use it
Useful when a coding agent needs quick, offline network calculations or lookups while working on networking, infrastructure or security tasks, and when you want DNS, blocklist, certificate or public-IP checks without leaving the assistant. The local calculators need no network at all.
Requirements
Runs as a local stdio process, either via npx (Node 18 or newer) or as a Docker image. No account, API key, environment variable or header is declared. The DNS, blocklist, TLS and public-IP tools need outbound network access to public resolvers and endpoints.
Before you install
The network tools contact third-party public services (Cloudflare resolvers and trace endpoint, Google DNS-over-HTTPS, Team Cymru ASN DNS) and whichever host you point the TLS inspection at, so queried hostnames and addresses leave your machine. TLS inspection refuses targets resolving to private or reserved space. It cannot test whether your own port is reachable from outside; the README points to the website for that.

Installation

In SourceWeft

  1. Open whatismynetip in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

netip-mcp

The whatismynetip.com toolbox as tools your coding agent can call. Subnet math, "what runs on this port and should it be open", MAC vendor lookups, DNS and blocklist checks, the certificate a host actually serves, and the IP the internet sees you as.

Free, MIT, no account, no telemetry. The site's own tools run in your browser; this runs the same logic next to your agent.

Install

Pin the version.

Claude Code

claude mcp add netip -- npx -y github:labaccessnow/netip-mcp#v0.1.0

Claude Desktop, Cursor, or any client with a JSON config

json
{  "mcpServers": {    "netip": {      "command": "npx",      "args": ["-y", "github:labaccessnow/netip-mcp#v0.1.0"]    }  }}

Docker

json
{  "mcpServers": {    "netip": {      "command": "docker",      "args": ["run", "-i", "--rm", "ghcr.io/labaccessnow/netip-mcp:0.1.0"]    }  }}

Node 18 or newer for the npx route. Also in the official MCP registry as io.github.labaccessnow/netip-mcp.

Tools

ToolWhat it answersNetwork
subnet_calcNetwork, mask, wildcard, broadcast, host range and counts for a CIDR — IPv4 and IPv6, /31 and /32 done rightnone
ip_in_subnetIs this address inside that block?none
ip_convertIPv4 as dotted, integer, hex, binary — from any of themnone
ipv6_normalizeExpanded and RFC 5952 compressed forms, and what kind of address it isnone
mac_lookupVendor from the full IEEE registry (~40,000 assignments, bundled), plus the multicast and locally-administered bitsnone
lookup_portWhat runs on a port, and whether to expose it — 100 ports written up by hand, searchable by servicenone
dns_lookupA, AAAA, MX, TXT, NS, CNAME, CAA, SOA, PTR, SRV over DNS-over-HTTPSDoH
reverse_dnsPTR for an IPv4 or IPv6 addressDoH
dnsbl_checkFive common blocklists, honest about the ones that refuse public resolversDoH
tls_inspectThe certificate a host actually serves: expiry, SANs, chain verification, protocol, cipherdirect TLS
my_public_ipThe address the internet sees, edge location, ASN, reverse DNS, datacenter/VPN hintCloudflare trace + Team Cymru DNS

lookup_port

The one I reach for most. The port pages on the site are opinionated — every port carries a verdict:

Port 3389/tcp+udp — RDP (Remote Desktop Protocol)
  Category   remote access  Software   Windows Remote Desktop Services, xrdp, FreeRDP server, Windows Admin Center hosts  Exposure   NEVER — do not expose to the internet
Internet-facing RDP is the most common initial-access route for ransomware crews, whocredential-stuff it around the clock; put it behind WireGuard, Tailscale or an RD Gateway …

Ask by number, or search: lookup_port with query: "redis" finds 6379. detail: true adds the full write-up and FAQ.

What it does not do

  • No account, no signup, no key.
  • No telemetry. Nothing about your usage goes anywhere.
  • Nothing of yours is read from disk. The only file it opens is its own bundled OUI table.
  • The local tools never open a socket. The network tools talk only to public services — Cloudflare and Google's DNS-over-HTTPS resolvers, Cloudflare's trace endpoint, Team Cymru's ASN DNS, and whichever host you point tls_inspect at. tls_inspect refuses anything that resolves to private or reserved space, so it cannot be turned on your own network.
  • "Is my port reachable from outside?" needs a machine outside your NAT to try the connection. That is what whatismynetip.com/port-checker does; a local tool cannot.

The port data and the calculators are the same ones the site uses, so the two stay in step.

Licence

MIT. Written by James Son — network, security, and automation engineer. Corrections and additions to the port write-ups are welcome.

Source: README.md at commit 6283b2e

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts