Ignore the error, it's not important. It's just a consequence of not using the vendor kernel. It still works.
Code:
# iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
ssh-drop tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 flags:0x17/0x02 recent: UPDATE seconds: 60 hit_count: 5 name: ssh side: source
tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 flags:0x17/0x02 recent: SET name: ssh side: source
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
Chain ssh-drop (1 references)
target prot opt source destination
LOG all -- 0.0.0.0/0 0.0.0.0/0 limit: avg 2/min burst 5 LOG flags 0 level 4 prefix `FIREWALL:SSH-DROPPED '
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
# service iptables restart
Flushing firewall rules: [ OK ]
Setting chains to policy ACCEPT: security raw nat mangle filter [FAILED]
Unloading iptables modules: [ OK ]
Applying iptables firewall rules: [ OK ]
Loading additional iptables modules: ip_conntrack_netbios_ns [FAILED]
# iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
ssh-drop tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 flags:0x17/0x02 recent: UPDATE seconds: 60 hit_count: 5 name: ssh side: source
tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 flags:0x17/0x02 recent: SET name: ssh side: source
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
Chain ssh-drop (1 references)
target prot opt source destination
LOG all -- 0.0.0.0/0 0.0.0.0/0 limit: avg 2/min burst 5 LOG flags 0 level 4 prefix `FIREWALL:SSH-DROPPED '
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable