block broadcast traffic

[George Liu <George.Liu@xxxxxxxx>]

I tried to use iptables to block inbound and outbound netbios broadcast 
announcement traffic of a system with IP 10.1.1.76. It seems iptables 
doesn't work. Is this a limitation or rule wrong? Thanks.



*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT

-A RH-Firewall-1-INPUT -s 10.1.1.0/22 -p udp -m multiport --ports 
135,136,237,138,139,445 -j REJECT
-A RH-Firewall-1-INPUT -d 10.1.1.0/22 -p udp -m multiport --ports 
135,136,237,138,139,445 -j REJECT
-A RH-Firewall-1-INPUT -p udp -m multiport --ports 
135,136,237,138,139,445 -j REJECT