[nsp] High-availabity GigE connection to two switches

[Gert Doering]

Hi,

On Tue, Jun 01, 2004 at 01:07:19PM -0500, Church, Chuck wrote:
> Depending on the NICs and the OS, you may be able to do a fail-over
> teaming setup.  I know 3Com, Intel, and Compaq/HP support this.  There
> are variations in design, but they work similar to HSRP, where one is
> active and the others lay and wait for missing keepalives from the
> active NIC.  Once it appears to be down, a standby NIC takes over and
> assumes the old NIC's MAC address, so that no ARP re-learning has to
> occur.

How do these solution detect a "down" situation on the primary link?  Only
by monitoring for the ethernet heartbeat, or by actively monitoring for
packets and/or sending null loopback packets?

I'm curious, because "just monitoring for ethernet link" isn't overly
helpful in the case of a switch supervisor breakdown - the modules are
likely to still send a link, while the actual frame forwarding will
break...

gert
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de