I need to forward (route) broadcast packets from several wireless clients to a single server in the fixed network. The wireless and fixed network are not bridged for security reasons.
With the following lines the packets show up in the INPUT chain log
iptables -I INPUT -i $IF_WIFI -p udp --dport 6000 -j LOG --log-prefix "I " iptables -I FORWARD -i $IF_WIFI -p udp --dport 6000 -j LOG --log-prefix "F "
Now I add the following rule
iptables -t nat -A PREROUTING -p udp -d 255.255.255.255 --dport 6000 -j DNAT --to 10.0.0.10:6000
Now the packets won't show up either in the INPUT or the FORWARD log and do not get routed to the fixed network. I would expect to see the packet in the FORWARD log
The PREROUTING rule gets hit according to
iptables -t nat -v --list Chain PREROUTING (policy ACCEPT 466 packets, 28575 bytes) pkts bytes target prot opt in out source destination 404 25819 DNAT udp -- any any anywhere 255.255.255.255 udp dpt:6000 to:10.0.0.10:6000
(update) IP forwarding is enabled
# cat /proc/sys/net/ipv4/ip_forward 1
Have I overlooked something?