How to enable CONFIG_NETFILTER in Kernel?

Question

I'm trying to install my own Firewall on ubuntu using iptables. In a tutorial it says, I need the iptables-Kernelmodule and the parameter CONFIG_NETFILTER=Y in Kernel Configuration. I didn't found a tutorial on web how to edit the Kernel Configuration. Results on Google were to compile an own Kernel, but I just want to edit one Config-Point, so I don't want to make big changes so I thought that this method is the wrong and that there might be an easier/more suitable.

So how to enable the CONFIG_NETFILTER in my Kernel Configuration?/Where can I edit the Config?

Solution

If you are using an Ubuntu kernel, CONFIG_NETFILTER is already enabled for you.

The kernel configuration is only for compiling the kernel, no other reason.

grep CONFIG_NETFILTER= /boot/*config*

Should let you know if your kernel has it enabled or not. If you see this:

CONFIG_NETFILTER=y

It's enabled, if you see this:

# CONFIG_NETFILTER is not set

Or nothing, CONFIG_NETFILTER is not enabled and the only way to enable it is to re-compile your kernel:

apt install build-essential libqt4-dev libncurses5-dev git tmux bc libncurses5 libncurses5-dev
git clone --depth 1 git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
cd linux
make menuconfig # this bit lets you enable the stuff you want.
make
make modules_install
cp zImage /boot/

this assumes a Debian like system that has mainline support.

Comments

[HelloToYou]

I found the config is at /boot/config.txt, it is a good way to change the config using nano?

[HelloToYou]

CONFIG_NETFILTER is not in the config.txt ...