Re: LibIPQ issue

[Patrick McHardy <kaber@trash.net>]

Sérgio Bernardino wrote:
> After a bit more time working with this i realized something "interesting":
> When i send a packet from a machine A to a machine B and capture it in
> PRE_ROUTING, if i change the destination address so that it points to
> machine C, the packet disappears and i can't track it anywhere. On the
> other hand, if i instead change the source address of the packet so
> that it points to machine C everything works fine. I can "see" the
> packet traversing into machine B, which receives the packet and
> promptly replies sending a packet to machine C. Machine A never
> receives a reply to the packet it sent and machine C receives a reply
> from a packet it never sent. Exactly the behaviour expected when
> changing the source address field. Now, if this works in this case,
> merely changing it to alter the destination address (my original
> intention) should work also, but it doesn't.
> My code can't be incorrect in a situation like this, so what exactly
> is wrong? And is there a away to solve such situation?
> Ideas anyone?

Have you got IP forwarding enabled ?

echo 1 >/proc/sys/net/ipv4/ip_forward

Regards
Patrick