Crashing Nameservers

[webmaster at ew3d.com (John Hinton)]

Had two nameservers crash in the last few hours... This 'never' happens! 
On the console was

sent an invalid ICMP type 3, code 3 error to a broadcast: 
255.255.255.255 on eth0

sent an invalid ICMP type 3, code 3 error to a broadcast: 
255.255.254.255 on eth0

with the IP address of the offender? in front of that line. Any ideas?

Best,
John Hinton