Hello, I'm using lastest 2.4.x kernel (no pom patch) with 2 100M NICs as firewall for about 1 year, with about 200 lines of rules . It works well. Yesterday I installed just about 10 rules in my chain, Linux box accidently panic under normal circumtences without notification ( there 's no high load,no high interrupt rate). I installed kernel 2.4.21 and it lived for 5 min to 3 hours but still panic randomly. Here is my iptalbles rule: # define a oneway rule for protect inside network iptables -N oneway iptables -A oneway -o eth1 -p dup -j ACCEPT iptables -A oneway -o eth1 -p tcp -m tcp --dport 80 -j ACCEPT iptables -A oneway -o eth1 -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -A oneway -o eth1 -p icmp -j ACCEPT iptables -A oneway -o eth1 -j REJECT # protect these networks iptables -A FORWARD -d 218.88.128.0/20 -j oneway