I am trying to set up port forwarding on an armv7 (CyclonV) device with a custom yocto image using a Xenomai4 Kernel 6.1.137. Iptables tells me, I have no 'nat' table and need a different kernel. I do not have 'CONFIG_NF_NAT' in my kernel config at all. I searched through the kernel sources and found 'CONFIG_NF_NAT' only in the def-configs for arm/ezx, i386 and x86_64. Not im my config file though. I tried just putting CONFIG_NF_NAT in my config, the kernel is building with it, but it is still not working.
My Config is based on multi_v7_defconfig.
Can anyone please tell me, what I need in my kernel config to be able to set up port-forwarding with IP-Tables (NAT).
OK. Thank you. By redoing it all again to make some screenshots, I actually found what I was missing. "CONFIG_NF_CONNTRACK" is disabled by default on arm. Enabling it made NF_NAT available. My main mistake was, that I thought all possible options are always in the .config file just commented out if not active. This is obviously not the case. Thank you all.