Multilinking and/or load balancing

[Sm1]

Okay i have two possible configurations i would like know if possible:

1) Lets say i got a linux box with 3 network connections - i am looking for a way to set one of them to hand out NAT addresses, and route all data equally through the other two connections.

I am looking for something more along the lines of more of a multilinking connections than a load balancing sort of thing.

2) Lets say now instead i have 3 linux boxes - 2 with each two network cards, one for lan and one for internet. How about instead setting up this third box which also has two network cards to hand out NAT addresses on one of the cards and to route all traffic to the other two linux boxes equally.

This is more of a load balancing approach than a multilinking approach, but i am looking for either way to work.




More important than anything i am looking for a bandwidth increase for users on the other end of this "router" linux box. It is my understanding that i should look more into multilinking than load balancing if i want to share bandwidth this way.


So how do-able is any of this?

[Sm1]

bump

[smart]

- what do you mean by "hand out NAT addresses"

<cite>
...and route all data equally through the other two connections.

I am looking for something more along the lines of more of a multilinking connections than a load balancing sort of thing.
</cite>

I feel a contradiction here... and don't get it really. what's in the pot .. load balancing/redundancy/different QoS. What's your intention ?

- setup number two seems illogical if i get it right. it creates a single point of failer without adding sth. in. whatever the single/central/box does should also be possible on each of the actual router machines (if you want the redundancy) or just on one single box. If you want to go with two machines offering redundancy i'd think of a setup of two machines, each equipped with 3 NICs, two of which go to both of the two Internet links and on for the LAN. On the LAN side you might either want to run a routing protocol or add a virtual IP to the pot.

All in all, i don't get your plan.

[Sm1]

The point is not for redundency - it is much more for sharing bandwidth of several connections. The machine with several lan cards/internet connections is indeed going to be a router ( and thus using NaT to hand out local addresses ).


By my current understand - i am going to forget the idea of setup number 2 and stick with setup 1 to get things working.

I was talking to somebody about this, and they kept claiming that there are several ways to set up load balancing that there is one where it would alternate every connection made from the router machine on the different internet connections. They also were telling me what i thought was the multilinking was actually "teaming" the cards together.

But let me re-iterate once more - i am looking for bandwidth combination, not redundency.

[smart]

AFAIK teh word "teaming" is normally used for an advanced feature of very advanced (read expensive) switches/intelligent routers. That's probably not your case.
You will though, be able to do "kind of" load balancing. As you suggested yourself, based on IP connections/alternating the path.
What you're probably looking for is called advanced routing in kernel terms, you might want to google for the "advanced routing howto".

[Sm1]

okay thank you very much.