First, thanks to anybody for the help.
In fact, the solution of chechito is the best option for this type of firewall, because the DFL-210 has all mechanisms to drop this type of events without rules.
But the solution of Fatman is more generalist and very interesting, more technical based on performance of devices, and is applied to all kinds of firewalls, in other words, no necessary DLink firewalls.
Thank you very much chechito and Fatman, "Medal of Honor" for both.
Juanjo