+ * command failed to terminate nicely?
+ * command failed (but terminated)?
+ * and if we find we have a NATed IP address).
+ * Handle to our operation to run `external-ip`.
+ * What is our external IP address as claimed by `external-ip`?
+ * 0 for unknown.
+  GNUNET_break (0); // FIXME: implement!
+ * address and pass it to NATed clients if possible.
+ * #run_external_ip with an appropriate timeout.
* Task we run periodically to scan for network interfaces.