IP Forwarding: Att: Mike Burger

[Jyce]

I think that 'route add -net 172.16.4.0 netmask 0xffffff00 gw 172.16.3.10'
should do the trick

HTH
>
> Hello,
>
> I did the 'ip addr' command. The result is as follows:
>
> [root at localhost root]# ip addr
> 1: lo: <LOOPBACK,UP> mtu 16436 qdisc noqueue
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>     inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
>
> 2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100
>     link/ether 00:60:97:df:8a:82 brd ff:ff:ff:ff:ff:ff
>     inet 172.16.4.2/24 brd 172.16.4.255 scope global eth0
>
> 3: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 100
>     link/ether 00:06:5b:b5:86:a9 brd ff:ff:ff:ff:ff:ff
>     inet 172.16.3.10/24 brd 172.16.3.255 scope global eth1
>
>
> Issue:
>
> Is there a way so that I can forward the packets from the 172.16.4.0
network without having its IP address changed to 172.16.3.10, which is the
so called "external interfce" for me.
>
>
> Network set up: (Strictly private)
>
> The redhat 9 gateway forwards traffic between two private networks. The
network topology goes like this:
>
> 172.16.8.0/24 ------------ router ----------- 172.16.3.0/24 ------- |
Redaht 9 | ------- 172.16.4.0/24
>
> This is a strictly private network setup for doing some tests.
>
>
> I had posted this question earlier:
> -----------------------------------
>
> Hello,
>
> I am a fairly new person in Linux networking.
>
> The issue I got some responses was as follows:
> -------------------------------------------------------
> I have had some good help to enable IP forwarding on my Redhat 9
> gateway with the rule:
>
> [CODE]iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to-source
172.16.3.10[/CODE]
>
> This rule forwards the traffic from the internal network (172.16.4.0/24)
to the
> outside trhough the NIC with IP address 172.16.3.10.
>
> Problem:
>
> But I feel that the internal IPs are being forwarded with the IP address
of the
> external NIC of the gateway.
>
> It would be helpful if I could have a way to keep the internal IP address
> (172.16.4.0)as it is without being substituted with the gateways IP
> address(172.16.3.10). This is because I want the external users to see the
> internal machines(172.16.4.0 network) as it is.
>
> Please advise.
>
> Thank You.
>
> Menon
>

-- 
Cordialement,
Jean-Christophe VALIERE