my router emails me: Smurf

Hi,

Anybody can explain to me why my router is mailing this warnings to me (few times daily), especially with this non-public IP adres
I got other warning emails as well, but from public IP adresses.

TIA, Gerard

Dear User
Your router has detected and protected you against an attempt to gain access to your network. This may have been an attempted hacker intrusion, or perhaps just your Internet Service Provider doing routine network maintenance.
Most of these network probes are nothing to be worried about - these types of random probes should NOT be reported, but you may want to report repeated intrusions attempts. Save this email for comparison with future alert messages.
Your router Alert Information

Time: 09/10/2006, 20:50:03
Message: Smurf
Source: 192.168.2.255, 0
Destination:255.255.255.255, 0 (from LAN1 Inbound)