Corporate Reactions to Linux (fwd)

Allen Reese allen at
Wed Oct 13 16:39:09 GMT 1999

There is a company called xylan working on network hubs, and switches that
allow only certain mac address to connect to them and they encrypt the
data between the port and the hub.  :)

well looks like htey are now
alcatel internetworking....  

Allen Reese
Senior Software Engineer
Driversoft, Inc.
allen at

On Wed, 13 Oct 1999 ard at wrote:

> On Wed, Oct 13, 1999 at 06:00:23AM +1000, tschweikle at wrote:
> > A better way I am aware of is monitoring mac addresses inside your
> > LAN --- thus giving you the whole control about which computers
> > are allowed to access your network, putting the burden on you to
> > adapt every network hardware change and reconfigure your routers
> > and switches (cause this only makes sense if you close any ports
> > using unknown mac addresses).
> > 
> > But even this isn't waterproof: what about illegal computers using
> > old and known network cards?
> Well, it really does not matter what kind of cards you use. In my
> experience of ethernet driver programming, the toughest quest, next
> to getting documentation, is to obtain the MAC-address. MAC is purely
> software.
> As a matter of fact, plain redhat-linux has the MAC-address as one of
> its interface configuration parameters, and I am relying on that to
> get the proper IP address from the DHCP server of my cable-internet
> provider. And for my ethernet driver: I did not succeed in obtaining
> it from the EISA bios. So I documented to use
> ifconfig <eth> hw ether xx:xx:xx:xx:xx:xx
> before uping...
> > > you can then either email / page the administrator or run
> > > denial-of-service attacks against the offending server to take it down (a
> > > drastic and not highly recommended course of action).
> > If you do have token ring there would be a simple DoS: send it
> > a "close adapter" command. Some ethernet adapters do have this
> > command to.
> When using windows NT, a small token-ring packet containing too
> many entries (I thought the RIP packet containing more than 7 entries),
> will crash an entire segment of NT based systems. And no tracing of
> who did it...
> I guess there is no security on ethernet based networks on which there
> is no form of encryption used. The only save way is probably to use
> encrypted communications between each computer, of course with strong
> public/private key authentication.

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