Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I have been stuck on this issue for two days now and couldnt find a fix for this. I installed a realtime kernel with

sudo apt-get install linux-rt

because KauNet (which is an ipfw extension) requires a real-time kernel for millisecond granularity.

However after trying to install KauNet I get this error message:

ERROR: Kernel configuration is invalid.
include/linux/autoconf.h or include/config/auto.conf are missing
Run 'make oldconfig && make prepare' on kernel src to fix it.

Both files are there. auto.confcan be found in /usr/src/linux-headers-2.6.31-10-rt/include/config and autoconf.h is in /usr/src/linux-headers-2.6.31-10-rt/include/linux.

Before I installed 2.6.31-10-rt kernel i was on 2.6.32-21-generic and KauNet/ipfw was working.

I appreciate any help. Thanks.

share|improve this question

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.