I am trying to send igmp traffic from eth1 to eth0. So in ip_route_input() I check if (MULTICAST(daddr)&&skb->nh.iph->protocol == IPPROTO_IGMP) and the input device is eth1 then I copy it to eth0. The weird thing is that it only works if I do a tcpdump on eth1. I have some printk statements and the multicast packets dont get to ip_route_input unless tcpdump is running. I am not running a multicast router. If anyone has any ideas I would appreciate the help. Thanks. __________________________________________________________________ Switch to Netscape Internet Service. As low as $9.95 a month -- Sign up today at http://isp.netscape.com/register Netscape. Just the Net You Need. New! Netscape Toolbar for Internet Explorer Search from anywhere on the Web and block those annoying pop-ups. Download now at http://channels.netscape.com/ns/search/install.jsp - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html