Lo de staff fue un grave lapsus, lo sorry. Hace muuuuuchos años que ni hablo ni escribo en ingles, uno tiene ya una edad, sabes?. Respecto a la españolizacion por contracciones discrepo, los motivos para escribir asi son otros. Pero, si te parece, dejemos la linguistica.
Por las respuestasanteriores, a proposito muchas gracias, me parece entender que cada router tiene una forma diferente de proteger accesos y que no hay grandes diferencias en niveles de seguridad entre ellas. Mi duda inicial, despues de leer la pagina www.grc.com se planteaba por .....como parece ser que no andamos mal de ingles, reproduzco los comentarios de Steve Gibson tal cual,
If all of the tested ports were shown to have stealth status, then for all intents and purposes your computer doesn't exist to scanners on the Internet!
It means that either your computer is turned off or disconnected from the Net or an effective stealth firewall is blocking all unauthorized external contact with your computer. This means that it is completely opaque to random scans and direct assault. Even if this machine had previously been scanned and logged by a would-be intruder, a methodical return to this IP address will lead any attacker to believe that your machine is turned off, disconnected, or no longer exists. You couldn't ask for anything better.
There's one additional benefit: scanners are actually hurt by probing this machine! You may have noticed how slowly the probing proceeded. This was caused by your firewall! It was required, since your firewall is discarding the connection-attempt messages sent to your ports. A non-firewalled PC responds immediately that a connection is either refused or accepted, telling a scanner that it's found a live one ... and allowing it to get on with its scanning. But your firewall is acting like a black hole for TCP/IP packets! This means that it's necessary for a scanner to sit around and wait for the maximum round-trip time possible — across the entire Net, into your machine, and back again — before it can safely conclude that there's no computer at the other end. That's very cool.
"Closed" is the best you can hope for without a stealth firewall in place.
Anyone scanning past your IP address will immediately detect your PC, but "closed" ports will quickly refuse connection attempts. Your computer might still be crashed or compromised through a number of known TCP/IP stack vulnerabilities. Also, since it's much faster for a scanner to re-scan a machine that's known to exist, the presence of your machine might be logged for further scrutiny at a later time — for example, when a new TCP/IP stack vulnerability is discovered.
You should stay current with updates from your operating system vendor since new "exploits" are being continually discovered and they are first applied upon known-to-exist machines . . . like this one!
AS NOTED ABOVE: If your system did NOT show up as Stealth! but you wish that it could, you will need to use one of the inexpensive personal firewalls I've discovered. If your system's security is a concern (as I'm afraid it needs to be in this day and age), I would advise you not to wait!
Sin entrar en traducciones literarias vs literales, de lo anterior entiendo que los puertos "close" tienen riesgos concretos frente a una mayor seguridad de los puertos stealth. Si estos es así, de nuevo pregunto ¿Se puede configurar el router para este nivel de seguridad?