[114432] in North American Network Operators' Group
Re: two interfaces one subnet
daemon@ATHENA.MIT.EDU (Alex H. Ryu)
Mon May 11 17:20:06 2009
Date: Mon, 11 May 2009 16:19:56 -0500
From: "Alex H. Ryu" <r.hyunseog@ieee.org>
To: Chris Meidinger <cmeidinger@sendmail.com>
In-Reply-To: <4B3726C0-20FE-4598-B4DA-44FA74FDFC71@sendmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Unless you configure Layer 2 for two interfaces, it's not going to work.
It is invalid from networking principle.
If you have to send the traffic for host in same subnet you configured,
which interface it should send out ?
Basically it may create broadcast storm loop by putting two ip addresses
in same subnet in different interface.
It may be allowed from host-level, but from router equipment, I don't
think it was allowed at all.
Alex
Chris Meidinger wrote:
> Hi,
>
> This is a pretty moronic question, but I've been searching RFC's
> on-and-off for a couple of weeks and can't find an answer. So I'm
> hoping someone here will know it offhand.
>
> I've been looking through RFC's trying to find a clear statement that
> having two interfaces in the same subnet does not work, but can't find
> it that statement anywhere.
>
> The OS in this case is Linux. I know it can be done with clever
> routing and prioritization and such, but this has to do with vanilla
> config, just setting up two interfaces in one network.
>
> I would be grateful for a pointer to such an RFC statement, assuming
> it exists.
>
> Thanks!
>
> Chris
>
>
>
