labaccessnow/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 Desktop, Cursor, or any client with a JSON config**
**Docker**
Node 18 or newer for the npx route. Also in the official MCP registry as io.github.labaccessnow/netip-mcp.
Tools
| Tool | What it answers | Network |
|---|---|---|
| subnet_calc | Network, mask, wildcard, broadcast, host range and counts for a CIDR — IPv4 and IPv6, /31 and /32 done right | none |
| ip_in_subnet | Is this address inside that block? | none |
| ip_convert | IPv4 as dotted, integer, hex, binary — from any of them | none |
| ipv6_normalize | Expanded and RFC 5952 compressed forms, and what kind of address it is | none |
| mac_lookup | Vendor from the full IEEE registry (~40,000 assignments, bundled), plus the multicast and locally-administered bits | none |
| lookup_port | What runs on a port, and whether to expose it — 100 ports written up by hand, searchable by service | none |
| dns_lookup | A, AAAA, MX, TXT, NS, CNAME, CAA, SOA, PTR, SRV over DNS-over-HTTPS | DoH |
| reverse_dns | PTR for an IPv4 or IPv6 address | DoH |
| dnsbl_check | Five common blocklists, honest about the ones that refuse public resolvers | DoH |
| tls_inspect | The certificate a host actually serves: expiry, SANs, chain verification, protocol, cipher | direct TLS |
| my_public_ip | The address the internet sees, edge location, ASN, reverse DNS, datacenter/VPN hint | Cloudflare 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:
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