Planet Networks Net Tools

  curl ip.ops.planet.net          your IP (whichever protocol you connect with)
  curl ipv4.ops.planet.net        your IPv4 address
  curl ipv6.ops.planet.net        your IPv6 address
  curl ptr.ops.planet.net         reverse DNS of your IP
  curl trace.ops.planet.net       traceroute back to you (IPs only)
  curl traceroute.ops.planet.net  traceroute back to you (with hostnames)
  curl headers.ops.planet.net     your request headers, as JSON
  curl proxy.ops.planet.net       proxy headers seen, as JSON (empty if none)
  curl epoch.ops.planet.net       current Unix time

Add -4 or -6 to pick the protocol.