iptables won't start and missing /proc/modules

Question

I had a perfectly working iptables but after server restart it won't start giving me Setting chains to policy ACCEPT: security raw nat mangle fi[FAILED] error.
I haven't changed anything in /etc/iptables.

I uninstalled iptables yum uninstall iptables and installed it again.

Now it's even worse :( I'm getting:

Flushing firewall rules:                                   [  OK  ]
Setting chains to policy ACCEPT: security raw nat mangle fi[FAILED]
Unloading iptables modules: Opening /proc/modules: No such file or directory
grep: /proc/modules: No such file or directory
Opening /proc/modules: No such file or directory
grep: /proc/modules: No such file or directory

How come /proc/modules is missing now?

I'm using CentOS 5. My iptables rules:

iptables -F INPUT
iptables -F OUTPUT

IPT="iptables"
ALLOWED="
XXX.XXX.XXX.XXX #list of allowed IP addresses
"

$IPT -I INPUT -p tcp --dport 80 -j ACCEPT
$IPT -I INPUT -p tcp --dport 443 -j ACCEPT

$IPT -I INPUT -p tcp --dport 3456 -j ACCEPT

for ip in $ALLOWED
do
    $IPT -I INPUT -p tcp -s $ip -j ACCEPT
done

$IPT -A INPUT -m state --state ESTABLISHED -j ACCEPT

$IPT -A INPUT -p icmp --icmp-type echo-request -m limit --limit 5/s -j ACCEPT

$IPT -A INPUT -i lo -j ACCEPT
$IPT -A OUTPUT -o lo -j ACCEPT

$IPT -A INPUT -p tcp --dport 53 -j ACCEPT
$IPT -A INPUT -p udp --dport 53 -j ACCEPT

What should I do?

Answer 1

First check why your /proc/modules is not available ! /proc is it mounted ? remount it if not are you root ? on my Ubuntu, everybody can read /proc/modules. Do you change your kernel before rebooting ? If yes, this new kernel is maybe incomplete (or doesn't support /proc, or the modules). Do you have iptables compiled in kernel or in modules ?