Forwarding not work in FC9 but ip forward is turn on

[Roger Grosswiler]

<snip>
>> [root at marte [2] ~]# netstat -nr
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
>> 192.168.5.0     0.0.0.0         255.255.255.0   U         0 0          0 eth4
>> 192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth5
>> 192.168.10.0    0.0.0.0         255.255.255.0   U         0 0          0 eth6
>> 169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth6
>>
>> [root at marte [5] ~]# iptables -L -n -v
>> Chain INPUT (policy ACCEPT 1758 packets, 182K bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain FORWARD (policy ACCEPT 89 packets, 6036 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain OUTPUT (policy ACCEPT 600 packets, 69134 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>> [root at marte [6] ~]# iptables -L -n -v -t nat
>> Chain PREROUTING (policy ACCEPT 1006 packets, 135K bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain POSTROUTING (policy ACCEPT 92 packets, 6288 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain OUTPUT (policy ACCEPT 4 packets, 312 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>> [root at marte [7] ~]# iptables -L -n -v -t nat -t mangle
>> Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
>> Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
>>  pkts bytes target     prot opt in     out     source               destination
>>
</snip>

1) there is no default gateway entered in your netstat -nr command. Gateway 0.0.0.0 is
missing in your routing table. So, where do you expect to go your traffic to?

2) you need the appropiate entries for accepting connections with iptables. just setting
the ip.forward.v4 param is not that enough (IMHO). Use system-config-firewall:
- set the NIC you want to accept connection as a trusted device (for test purposes now)
- add a forward rule to the nic, you want to to forward, such as :
iptables -A FORWARD -i [NIC_TO_FORWARD] -j ACCEPT

Try, then you should see using iptables -L -v some traffic on the NIC and in the FORWARD
state.

HTH
Roger