Subject: Re: load balancing ethernet
To: Chris Jones <>
From: Skeelo <>
List: current-users
Date: 07/22/1998 01:35:55

As I was checking out someone's great work in collecting information on
various organizations/projects that use NetBSD, I came across this.

Being the curious creature that I am I started reading. It's very
interesting and might be just what you are looking for.

Hope this helps.

On Tue, 21 Jul 1998, Chris Jones wrote:

> I sent this query to tech-net, and didn't get much response.  I did,
> however, get email from somebody else who wants to know what I find out
> about this.  Maybe somebody on this (higher-traffic) list can help...
> In my new job, we just got a grant to build a "distributed compute
> cluster."  (We don't *really* know what that means, but it looked good on
> paper.  :-)  As the admin for the group, I'm trying to get this to happen
> with NetBSD, as I don't want to deal with a linux cluster.
> We don't know how much bandwidth we're going to need, but we think it will
> be approximately "lots."  One thing we're looking at is multiplexing 100bT
> ethernet.  (There are cards out there which have multiple fast ether
> interfaces on them -- I think I remember one by Adaptec.  I'll try to
> find out more about them at some point.)
> Anyway, NASA (and other groups) have projects such as Beowulf
> ( which do
> something they refer to as "channel bonding."
> (  Channel
> bonding is supposed to load-balance (or multiplex, or whatever you want to
> call it) multiple ethernet interfaces, so you can effectively multiply
> your bandwidth.
> Companies like Cisco and Cabletron have similar things that their switches
> can do (e.g.,  I
> don't know how these work, other than some vague mumbo-jumbo a Cabletron
> salesman just told me about doing strange things with MAC addresses.  But
> however they work, it seems to me that the OS is still going to need to
> understand what's going on.
> My actual question is, can we do something like this with NetBSD?  Really,
> we just want to maximize the bandwidth/dollar ratio.  ATM looks expensive,
> and 100bT may not have the bandwidth we need.  Is there a way to multiply
> your bandwidth?
> Obviously, we could just assign a different IP to each ether interface,
> and use DNS load-balancing, but that solution gives a bunch of little
> pipes to each machine.  We would really like to simulate a single, big
> pipe (with low latency) to each machine.
> Any thoughts?
> Chris
> Chris Jones                                
>            Mad scientist at large          
> "Is this going to be a stand-up programming session, sir, or another bug hunt?"