[U-Boot-Users] ethact, ethprim and NET_MULTI

Vadim Bendebury vbendeb at yahoo.com
Fri Mar 9 18:01:32 CET 2007

Sorry, Wolfgang, I missed your reply before sending an email on
another thread. Anyway, the thing is that quite often different
interfaces are connected to different subnets and switching interfaces
is completely useless.

IMHO it should be possible to disable this "autoswitch" behavior.


On 3/8/07, Wolfgang Denk <wd at denx.de> wrote:
> In message <917337.93885.qm at web302.biz.mail.mud.yahoo.com> you wrote:
> >
> > > What is the rationale behind this moving active
> > > interface at any
> > > (quite possibly non intentional) disturbance?
> >
> > Well, I can't speak to the author's original
> > intentions.  You've probably noticed that the TCP/IP
> > capabilities of U-boot are very limited.  A board has
> > a single address which is not bound to a specific
> > interface.
> I'm not  sure  what  you  mean  by  "single  address".  Each  network
> interface  has  it's  own  MAC  address,  which  often  is  mapped to
> different IP addresses (note that this is not  a  requirement  -  all
> interfaces could use the same IP address, too).
> > I expect that the most common use for Ethernet
> > connectivity is TFTP.  I guess it's assumed that you
> > have things cabled properly, and if not, you don't
> > care which interface is used to get your image.
> The intention is to provide support  for  redundant  network  connec-
> tions.  In  a  system with sevral interfaces you will be able to boot
> over the network even if one cablke breaks  or  one  TFTP  server  is
> down. The chosen timeout is a compromise between ebing long enough to
> allow for tempoorary network glitches and being short enough to allow
> for a reasonable fast boot in case of network problems on the primary
> / current interface.
> Note that the timeout is adjustable.
> Best regards,
> Wolfgang Denk
> --
> DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
> Office:  Kirchenstr. 5,       D-82194 Groebenzell,            Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> EMACS belongs in <sys/errno.h>: Editor too big!

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