升级了内核后 版本还降低了~~~~

xjjbb:/home/Ruby # iptables -A POSTROUTING -t nat -s 192.168.1.0/24 -o ppp0 -j MASQUERADE
iptables v1.3.6: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.