[Beowulf] raw ethernet

[Daniel Ridge]

Greetings,

On Jul 22, 2004, at 10:14 AM, Robert G. Brown wrote:

> But
>
>   a) Why invest all that time making a tool that will then be a priori
> limited to a private network and which will break things horribly and
> evilly if ever used (by accident or out of ignorance, say) on a
> non-private network?

Because the tool could be part of a cluster operating system
that expects a private interconnect. People can get easily hung
up on the fact that their cluster interconnect happens to be
made out of commodity components that, when used elsewhere,
could be attached to a local area network.

> Robustness is good, and IANA compliance is clearly more robust.  To 
> wit:

Waterproof is also more robust.

> c) It isn't that hard to do correctly. Even in the private network,
> the nodes will still need IP.

No they don't. I think you could correctly say that most of us
are limited to IP on our cluster interconnect.

The original poster is saying: "Hey, these cheap boards used for
networking have interesting properties. I wonder what you get
if you think differently about how to use them?"

Although there are many incomplete or abandoned projects that attempt
the same thing, the fact is that this impetus is no less ridiculous
than Hank Dietz' PAPERS -- a system that achieved impressive
performance numbers for some types of problem and was thought provoking.

>  It would probably take far more time to figure out how
> to override the NIC MAC addresses and build semi-robust utilities for
> doing so throughout a cluster.

ifconfig can set NIC MAC addresses. It's trivial.

Regards,
	Dan Ridge