Come settare "Modem ADSL2+ Wi-Fi N" per ignorare Echo request

[ElDrago]

Oggi ho sostituito il modem/router di Alice 20 Mega con un "Modem ADSL2+ Wi-Fi N" della Telecom (software AGPWI_1.0.3)

Fino a ieri, usando il vecchio modem "Pirelli" di Alice e settando opportunamente il mio Firewall COMODO CIS 5.5 per avere tutto stealthed, andando su GRCShieldsUP
https://www.grc.com/x/ne.dll?rh1dkyd2
facendo il test delle porte avevo un risultato perfetto (Passed)

Oggi invece con questo nuovo router vedo che c'è un "ping reply" che mi rovina tutto... e che fino a ieri non c'era

Solicited TCP Packets: PASSED — No TCP packets were received from your system as a direct result of our attempts to elicit some response from any of the ports listed below — they are all either fully stealthed or blocked by your ISP. However . . .

Unsolicited Packets: PASSED — No Internet packets of any sort were received from your system as a side-effect of our attempts to elicit some response from any of the ports listed above. Some questionable personal security systems expose their users by attempting to "counter-probe the prober", thus revealing themselves. But your system remained wisely silent. (Except for the fact that not all of its ports are completely stealthed as shown below.)

Ping Reply: RECEIVED (FAILED) — Your system REPLIED to our Ping (ICMP Echo) requests, making it visible on the Internet. Most personal firewalls can be configured to block, drop, and ignore such ping requests in order to better hide systems from hackers. This is highly recommended since "Ping" is among the oldest and most common methods used to locate systems prior to further exploitation.

Qualcuno sa cosa (e dove) settare nel modem per ignorare gli ICMP Echo requests?

Ovvero, se quello che GRCShieldsUp sta pingando è il router (intendo l'accessorio "fisico") come faccio a fargli pingare (e quindi non rispondere all'Echo Request, perché così è settato COMODO) il mio firewall/PC?