# is-port-515-open

> is-port-515-open is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Checks whether TCP port 515 (LPD/Line Printer Daemon) is open, closed, or filtered on a given host, reporting connect time from Cloudflare's edge.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/ip/port/515?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-port-515-open-e3de60ec
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tXfGOT-ca65CrpzMHgEyP

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability is-port-515-open-e3de60ec
```

Example prompt: Can you check whether TCP port 515 (LPD) is open or closed on the host 203.0.113.45 — I want to know if the line printer daemon port is accidentally exposed without running my own scanner.

## When to prefer this

Use this endpoint when you need a quick, passive LPD port exposure check from an external vantage point without deploying your own network scanner. It is ideal for security audits, compliance checks, or post-firewall-change verification where you want a third-party perspective on port 515 reachability. Prefer alternatives if you need comprehensive port range scanning or need to test ports on Cloudflare-fronted infrastructure where results will be inconclusive.

## Known failure modes

- Cloudflare-fronted hosts return inconclusive status because Cloudflare's edge intercepts the connection
- Firewalled hosts may appear filtered rather than closed, making the distinction ambiguous
- Hosts behind NAT or reverse proxies may not reflect true port exposure
- Network timeouts may cause false filtered results for slow-responding hosts
- Invalid or unresolvable hostnames will result in an error response

## How this service works

Is TCP port 515 (LPD) open on a host? Attempts a connection from Cloudflare's edge and reports open/closed/filtered with the connect time; Cloudflare-fronted hosts are reported as inconclusive because their edge answers for them. Exposure checks for LPD without running a scanner. $0.01 per check.

## Output

Returns whether TCP port 515 is open, closed, or filtered on the target host as seen from Cloudflare's edge network, along with the connection time in milliseconds. If the host is Cloudflare-fronted, the result is marked inconclusive since Cloudflare's edge answers on behalf of the origin.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/is-port-515-open-e3de60ec/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ip.intel.rallylive.ca](https://www.zero.xyz/host/ip.intel.rallylive.ca/llms.txt)