[plug] Routing and two ethernat adapters.

Matt Kemner zombie at networx.net.au
Thu Sep 24 10:52:38 WST 1998

On Thu, 24 Sep 1998, Lindsay Allen wrote:

> Hi Tony,
> I don't have anything running a 2.0.x kernel here at the moment so I can't
> check, but I thought that "/proc/sys/net/ipv4/ip_forward = 1" was just
> applicable to 2.1.x, in which case you will need ipchains. 

No anything after about 2.0.29 (or was it .30?) has the
/proc/sys/net/ipv4/ip_forward entry, which allows you to enable and
disable ip forwarding. The Kernel configuration scripts only set the
default (unlike the 2.1 series where you have to enable it in the kernel
config AND /proc/ to enable ip forwarding)

Tony, what do your routing tables look like on the 3 machines involved
(the two machines you're trying to ping between, and the gateway)
Also, have you tried running tcpdump on both network cards on the gateway?
you can use tcpdump -i eth1 to tell it to use the 2nd ethernet card.

 - Matt

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