multiple providers

Hi all,

I've seen Linux Advanced Routing & Traffic Control HOWTO concerning the
"Routing for multiple uplinks/providers" and I'd like to ask you a
question:

Is it possible to implement such a solution with two links with the same
provider (and the same ip network) ?

Internet Internet
| |
Provider1(IP1/NET) Provider1(IP2/NET)
\--------------+-------------/
|
Router


Even if the two external interfaces has the same external network,
I'd like to send back data coming from IP1 through IP1 and
datas coming from IP2 through IP2.

Do you think using ip route solve my problem ?

Thanks in advance for your help.

Sébastien
--
[ retirer NOSPAM pour répondre directement
remove NOSPAM to reply directly ]

On Tue, 08 Mar 2005 15:30:45 +0100, Sébastien Cottalorda
<(E-Mail Removed)> wrote:

>Hi all,
>
>I've seen Linux Advanced Routing & Traffic Control HOWTO concerning the
>"Routing for multiple uplinks/providers" and I'd like to ask you a
>question:
>
>Is it possible to implement such a solution with two links with the same
>provider (and the same ip network) ?
>
> Internet Internet
> | |
>Provider1(IP1/NET) Provider1(IP2/NET)
> \--------------+-------------/
> |
> Router
>
>Sébastien

Be specific:
1) Is IP1/MASK identical to IP2/MASK? If yes, how do you expect to
identify the traffic?
2) What is MASK?
3) How many NICs in Router? Where do they face?

I have never read the docs, but I suspect thay you should research
"ARP flux". You absolutely need to read about policy routing. Your
kernel will need Julian Anastasov's patch. http://www.ssi.bg/~ja/

It is possible to assign identical IPs to more than one NIC. When you
do that, netmasks become critical; you must not be sloppy with them.

I have gathered some links to documentation for traffic shaping and
multipath routing. Don't stop with this though, because there are
surely other sites I haven't yet found.
http://yesican.chsoft.biz/lartc/index.html

My experience: Spent an entire week, finishing last night, setting up
multipath, and that's after having done it once before about a year
and a half ago. Don't expect this to be quick or easy.
--
buck

buck a écrit :
> On Tue, 08 Mar 2005 15:30:45 +0100, Sébastien Cottalorda
> <(E-Mail Removed)> wrote:
>
>
>>Hi all,
>>
>>I've seen Linux Advanced Routing & Traffic Control HOWTO concerning the
>>"Routing for multiple uplinks/providers" and I'd like to ask you a
>>question:
>>
>>Is it possible to implement such a solution with two links with the same
>>provider (and the same ip network) ?

Internet Internet
| |
IP1 IP2
Router-Provider1(IP1/NET) Router-Provider1(IP2/NET)
IPI1 IPI2
\--------------+--------------/
|
IPI3
Router-LAN
|
Internal LAN
>>
>>Sébastien
>
>
> Be specific:
> 1) Is IP1/MASK identical to IP2/MASK? If yes, how do you expect to
> identify the traffic?

In fact say external Router-Provider1 IP1: 195.78.26.25
and external Router-Provider2 IP2: 195.78.26.27

Internal DMZ-Router-Provider1 IPI1: 192.168.0.1/255.255.255.0
Internal DMZ-Router-Provider2 IPI2: 192.168.0.2/255.255.255.0
DMZ-Router-LAN IPI3: 192.168.0.3/255.255.255.0
and
Internal LAN: 192.168.1.0/255.255.255.0
> 2) What is MASK?

???

> 3) How many NICs in Router? Where do they face?

The router has only one NIC but using aliases, I can configure 2 IP if
it's necessary (the link mentionned before did not precise such an manner).


> I have never read the docs, but I suspect thay you should research
> "ARP flux". You absolutely need to read about policy routing. Your
> kernel will need Julian Anastasov's patch. http://www.ssi.bg/~ja/
>
> It is possible to assign identical IPs to more than one NIC. When you
> do that, netmasks become critical; you must not be sloppy with them.
> I have gathered some links to documentation for traffic shaping and
> multipath routing. Don't stop with this though, because there are
> surely other sites I haven't yet found.
> http://yesican.chsoft.biz/lartc/index.html

It seems to be very interesting, but what I understood : every examples
shown 2 differents ISP with 2 different external IPs assigned.

> My experience: Spent an entire week, finishing last night, setting up
> multipath, and that's after having done it once before about a year
> and a half ago. Don't expect this to be quick or easy.

I don't think it'll be easy.
That kind of configuration is not for the newbies.

> --
> buck

Thanks buck.


Sebastien

On Tue, 08 Mar 2005 21:44:19 +0100, Sébastien Cottalorda
<(E-Mail Removed)> wrote:

>buck a écrit :
>> On Tue, 08 Mar 2005 15:30:45 +0100, Sébastien Cottalorda
>> <(E-Mail Removed)> wrote:
>>
>>>Hi all,
>>>Is it possible to implement such a solution with two links with the same
>>>provider (and the same ip network) ?
>
> Internet Internet
> | |
> IP1 IP2
>Router-Provider1(IP1/NET) Router-Provider1(IP2/NET)
> IPI1 IPI2
> \--------------+--------------/
> |
> IPI3
> Router-LAN
> |
> Internal LAN
>>>
>>>Sébastien
>>
>>
>> Be specific:
>> 1) Is IP1/MASK identical to IP2/MASK? If yes, how do you expect to
>> identify the traffic?
>
>In fact say external Router-Provider1 IP1: 195.78.26.25
> and external Router-Provider2 IP2: 195.78.26.27

>Internal DMZ-Router-Provider1 IPI1: 192.168.0.1/255.255.255.0
>Internal DMZ-Router-Provider2 IPI2: 192.168.0.2/255.255.255.0
> DMZ-Router-LAN IPI3: 192.168.0.3/255.255.255.0
>and
> Internal LAN: 192.168.1.0/255.255.255.0
>> 2) What is MASK?
>
>???

Your MASKs are 255.255.255.0 for the internal network. That is fine.
Now we need the same information for the 195.78 network. There is
also a gateway IP which I'm guessing has an IP of 195.78.26.30 and
your broadcast is .31. In that case, the mask is 255.255.255.248 and
the CIDR notation is /29. If your mask is 255.255.255.252 then you
are "stepping on" your gateway.

>> 3) How many NICs in Router? Where do they face?

>The router has only one NIC but using aliases, I can configure 2 IP if
>it's necessary (the link mentionned before did not precise such an manner).

Oops I have no experience with a setup where the internal and the
external networks are on the same NIC. I can't even get my tiny
little mind around that.

>It seems to be very interesting, but what I understood : every examples
>shown 2 differents ISP with 2 different external IPs assigned.

Yes, but that is what you have. One of your external IPs is the .25
and the other is .27. Nevermind that the ISP is the same.

When I say the following, I am ignoring that the internal network is
on the same NIC. I would install another NIC and put the LAN on it.

I think you will be fine. Download and read the Kurjata script from
yesican. It gives you the multipath routing you need. Download the
"working proxyARP startup script" and examine the ip link, ip address
add, and the ip route add commands. Don't use ifconfig. ifconfig
will give you wrong routing tables that you'll just have to delete.

>Thanks buck.
>
>
>Sebastien

Here is one more link. The 2 external networks each have 5 IPs so you
just skip the extras. Otherwise, you can pretty much just plug in
your information and run it. Note the /32s. Those and the routes to
the gateways are the key.

http://yesican.chsoft.biz/lartc/rc.nano1

Don't run the script until you have Julian's patch applied.
--
buck