Multihoming problem

Multihoming problem

[Javier A Toledano]

Hello To everyone:

I've setup a linux box with 3 ethernet cards.
One in the 10.0.0.0/8 net in the eth0,
the other in the 192.168.10.0/24 in the eth2 and
the other is connected to dsl modemwith with eth1.

I've setup forwarding with, net.ipv4.ip_forward = 1.
A strange phenomenon happens that I don't understantd. When I make an
echo request from a host in the net 10.0.0.0 to a host in the
192.168.10.0 the packet arrives to the eth0 interface but it seems
that it doesn't traverse the linux because with tcpdump I see no icmp
packet in eth2
But when a make an echo request from the 192.168.10.0 to a host in
10.0.0.0 , I receive the echo reply and, inmediatley the echo request
originated in 10.0.0.0 receives the echo replies from 192.168.10.0.

If would appreciate any idea, Sorry for my poor English.

Thanks in advance

Re: Multihoming problem

[Danny]

Hi,

Well, I have  done this !
What does route -n say ?

You would just need one iptable rule for masquerading outgoing requests 
through eth1. Do you have anything else ?

At 10.0.0.X host, do route -n : [ from where you are not able to ping to 
192.168.0.X ]


- Danny

Javier A Toledano wrote:
> Hello To everyone:
>
> I've setup a linux box with 3 ethernet cards.
> One in the 10.0.0.0/8 net in the eth0,
> the other in the 192.168.10.0/24 in the eth2 and
> the other is connected to dsl modemwith with eth1.
>
> I've setup forwarding with, net.ipv4.ip_forward = 1.
> A strange phenomenon happens that I don't understantd. When I make an
> echo request from a host in the net 10.0.0.0 to a host in the
> 192.168.10.0 the packet arrives to the eth0 interface but it seems
> that it doesn't traverse the linux because with tcpdump I see no icmp
> packet in eth2
> But when a make an echo request from the 192.168.10.0 to a host in
> 10.0.0.0 , I receive the echo reply and, inmediatley the echo request
> originated in 10.0.0.0 receives the echo replies from 192.168.10.0.
>
> If would appreciate any idea, Sorry for my poor English.
>
> Thanks in advance
>
>