MAE West

Mon Jul 14 05:53:45 UTC 1997

> On Fri, 11 Jul 1997, Rodney Joffe wrote:
> 
> > By the way, to expand the thread, I have the feeling that the three
> > OC-3s from NASA Ames side to MFS all go to GIGA 1, which then has fddi
> > loops to GIGA 2 and then to GIGA 3.
> > 
> > Does anyone know if this is the case?
> > 
> > If it is, seems that a better design would have been to route some of
> > the OC-3s to the other GIGAs first. If 1 is down, then it can't pass
> > traffic through to 2 and 3, so there is a single point of failure for
> > all the switches at MFS.
> 
> The Gigaswitch constrains us to a loop-free topology, so there's no way to
> avoid a single point of failure in a case like this.
> 
> The Gigaswitch systems in general have been quite reliable over the last
> few years, modulo individual line card failures.  The problems we tend to
> see are either load-related or caused by human error.  This is the first
> major outage caused by a Gigaswitch itself that we've seen in a very
> long time.
> 
> By the way, as of yesterday it's four OC3's between Ames and MFS.
> 	Steve
> 
> 
Steve,
	Are you telling me that the GigaSwitch, unlike every other bridge
since well before I became involved in networking, is incapable of spanning
tree?  I find that hard to believe.  Could anyone on the list from DEC
please confirm or deny this absurdity?

Owen