DNAT for two external NIC

["Ming-Ching Tiew" <mingching.tiew@redtone.com>]

Pascal Hambourg wrote :-

>Hello,
>
>Mikhail a écrit :
>>   Everything works fine if I use IP1 address but I was unable to get to the
>> corresponding LAN machine through IP2. Ping requests are also not responded
>> if they're made to IP2. They do reach eth2 and I can see them using tcpdump
>> but then nothing goes out on any NIC. The same goes for TCP/IP requests -
>> I've managed to trace them to the nat table PREROUTING chain but they could
>> not be found in either INPUT or FORWARD chain of the mangle table. If I make
> default route through eth2 - >everything starts working through that NIC and
>> stops through eth1.
>
>Maybe you need to disable rp_filter (reverse path filtering) on the
>interface that has not the default route.
>
>sysctl -w net/ipv4/conf/eth2/rp_filter=0

Isn't this a bug in rp_filter ? In multipath routing, it's often the system
will have multiple routing tables. The rp_filter seems to only look at
the main routing table.

Regards.