Hello CaptainData,
The ubuntu_config was made solely with the idea of enabling basic routing and does not include the wide number of iptables modules, neither are they enabled by default. To enable them, include the desired modules in your kernel config, i.e. to add the basic filter table enable:
CONFIG_IP_NF_FILTER=y
in your .config or enable IP_NF_FILTER via make menuconfig:
Symbol: IP_NF_FILTER [=y]
Type : tristate
Prompt: Packet filtering
Location:
-> Networking support (NET [=y])
-> Networking options
-> Network packet filtering framework (Netfilter) (NETFILTER [=y])
-> IP: Netfilter Configuration
(1) -> IP tables support (required for filtering/masq/NAT) (IP_NF_IPTABLES [=y])
Defined at net/ipv4/netfilter/Kconfig:231
Depends on: NET [=y] && INET [=y] && NETFILTER [=y] && IP_NF_IPTABLES [=y]
rebuild the kernel and boot Ubuntu with the newly build images.
