LARTC - Apr 2001 - Routing using 2 ISPs (one flatrate - the other not)

Hi!

I don''t know if this was discussed here already.

I have the following setup:


ISP1 2 MBit flat ----------- eth0 \
                                     -- Linux Box eth2 --- private LAN
ISP2 100 MBit non-flat ----- eth1 /


The Linux box is running 2.4.x with iptables and DNAT for the local network.

Now I want to do the following bandwith allocation:

All data should be transferred from/to the 2MBit ISP, where I don''t
have
to pay anything for my used bandwith (flatrate).

When the bandwith is filled up, I like to route all excess traffic 
through the ISP2 where I have to pay for all *incoming* traffic.

What is the best setup for this?

---

And now a little more complicated:

ISP1 2 MBit flat ----------- eth0 \                     / private LAN
                                     -- Linux Box eth2 --
ISP2 100 MBit non-flat ----- eth1 /                     \ ISP2 net

ISP2 net is a network, which is routed from ISP2 to my linux box.

Is there any possibility to route some of this traffic through the 2MBit 
link? I only have to pay for traffic which I receive *from* the internet.

-- 
Torge Szczepanek

Hello,

On Sun, Apr 29, 2001 at 02:57:53PM +0200, Torge Szczepanek wrote:
> ISP1 2 MBit flat ----------- eth0 \
>                                      -- Linux Box eth2 --- private LAN
> ISP2 100 MBit non-flat ----- eth1 /
> 
> All data should be transferred from/to the 2MBit ISP, where I
don''t have
> to pay anything for my used bandwith (flatrate).
> 
> When the bandwith is filled up, I like to route all excess traffic 
> through the ISP2 where I have to pay for all *incoming* traffic.
If ISP2 does not do anti-spoofing then you could send all your traffic
out through eth1 with the source of eth0 so that everything comes back
through eth0 (and you dont pay for your *incoming* traffic). This does
not answer to your question but is just a thought to consider.
> 
> ISP1 2 MBit flat ----------- eth0 \                     / private LAN
>                                      -- Linux Box eth2 --
> ISP2 100 MBit non-flat ----- eth1 /                     \ ISP2 net
> 
> ISP2 net is a network, which is routed from ISP2 to my linux box.
> 
> Is there any possibility to route some of this traffic through the 2MBit 
> link? I only have to pay for traffic which I receive *from* the internet.
if you say that you don''t have to pay for the traffic you send to IPS2,
why do you want to send some of your traffic to ISP1. But in general if you
want to do this then you must make sure that the packets (which have the
source of your "ISP2 net" will not get dropped by ISP1 because of
anti-spoofing.

Ramin