On Thu, Apr 28, 2005 at 05:47:42PM +0300, Rikunj wrote: > Thankyou for the reply. > > This was the log from one of my client who was attacked from a client on > other subnet. > > My network consist of clients from different subnets of /24. > > The attacks from one subnet travels through my linux router and hits the > client on other subnet. > > I tried few rules as below but seems not to be working. > > -----------Cut From fwscript.sh------------------------- > > echo 1 > /proc/sys/net/ipv4/tcp_syncookies > echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts > echo 0 > /proc/sys/net/ipv4/conf/all/log_martians > echo 0 > /proc/sys/net/ipv4/tcp_timestamps > echo 0 > /proc/sys/net/ipv4/conf/all/accept_redirects > echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts > echo 0 > /proc/sys/net/ipv4/conf/all/accept_source_route > echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses > iptables -F > iptables -t nat -F > iptables -t mangle -F > iptables -P FORWARD DROP > iptables -P OUTPUT ACCEPT > iptables -P INPUT DROP > iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT > iptables -A FORWARD -p icmp --icmp-type echo-request -m length --length > 92 -j DROP > iptables -A INPUT -i lo -j ACCEPT > iptables -A FORWARD -p tcp --syn -m limit --limit 10/s -j ACCEPT > iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT > iptables -A FORWARD -p ip -f -j DROP > iptables -A FORWARD -p tcp --tcp-flags ALL ACK,RST,SYN,FIN -j DROP > iptables -A FORWARD -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP > iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN,RST -j DROP > iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP > iptables -A INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j DROP > iptables -A INPUT -p tcp --tcp-flags ACK,FIN FIN -j DROP > iptables -A INPUT -p tcp --tcp-flags ACK,PSH PSH -j DROP > iptables -A INPUT -p tcp --tcp-flags ACK,URG URG -j DROP > ----------------------------------------------- well, you're really not blocking much of anything with that. if you wish to block 192.168.25.208: iptables -A FORWARD -s 192.168.25.208 -j DROP when they call to ask why "the Internet is down" invoke plan B--opening up a can of the genuine whoop-ass. -j -- "Peter: You wanna talk about awkward moments? Once, during sex, I called Lois "Frank". Your move, Sherlock." --Family Guy