You cannot prevent any upstream router/host from sending you any kind of packet (including ICMP broadcasts). What you can do is to ignore them but be carefull not to ignore legitimate ICMP's. What network are you on? The first broadcast is coming from 216.112.46.227 and the second one is coming from 194.85.34.35. At least this is what the DNS says which most definitely is wrong because the broadcasts should only have local significance. Ramin On Wed, Dec 03, 2003 at 12:21:41PM -0500, Aldo S. Lagana wrote: > I'm attempting to stop these types of broadcasts directed at a NIC that has > a registered IP address: > 12:13:26.670379 w227.z216112046.bos-ma.dsl.cnc.net > X.X.X.X: icmp: echo > request > 12:13:26.701129 w227.z216112046.bos-ma.dsl.cnc.net > X.X.X.X: icmp: echo > request > 12:13:26.710815 w227.z216112046.bos-ma.dsl.cnc.net > 255.255.255.255: icmp: > echo request > 12:13:27.192127 ns.majordomo.ru > 255.255.255.255: icmp: echo request > > I simply do not want those packets coming to my IP address - is it not > possible? I attempted to set the /proc variable about no icmp broadcasts, > but I still see the packets in a tcpdump - is this simply what you can call > a mini-dos in that the icmp probes are not really hitting the iptables > ruleset? These rules were no help: > iptables -t nat -I PREROUTING -i eth1 -p icmp -j DROP > iptables -I INPUT -i eth1 -p icmp -j DROP >
