<SWAG>
That would depend on what the VLAN represents in your drawing. Since I don't think
you can
have a VLAN without some type of switch, the 1st figure wouldn't make sense. You could
have
VLAN 100 and 200 on the same switch as the bottom picture suggests. The switch would
probably put the loser port into blocking mode.
BUT (assuming no auto sensing ISL/802.1q that would put them into trunking mode which
the
hub would just pass)
if you had 2 different switches connected to the hub, then which ever had the lowest
BID
might wind up having the root for one VLAN leaked through the hub to the next. Although
really freaky sounding though, it might not be that evil theoretically because you
would
still have a tree connected somewhere by this hub with no loops, just encompassing 2
VLANs.
They would pass on their conf BPDU updates like normal. When one station ARPed the
Gateway, it would get a response from the appropriate gateway and send traffic to that
MAC
which would get normally forwarded. It would depend on the rest of the topology. I
think it
just might be considered another area where one switch would have to be considered the
DB
with the DP unless the other was "downstream". In which case it might just figure it
the
"upstream" has a better cost to the root. Thinking about the topologies though and the
effects would give one a headache though...hehe.
</SWAG>
I like it, I might have to break some switches next week in the lab...
Larry
Brian wrote:
> On Thu, 27 Jul 2000 [EMAIL PROTECTED] wrote:
>
> >
> > Since we seen to be doing the Spanning Tree simulations today... Imagine
> > what happens when you have two instances of STP running, one per VLAN on
> > VLAN 100 and VLAN 200, and then hook both VLAN 100 and VLAN 200 to the same
> > hub. :-)
>
> if you just had it like this:
>
> /---------Hub----------\
> | |
> | |
> vlan 100 vlan 200
>
> then I don't think it would be too bad since I don't see where a storm
> could happen. But if you had like this:
>
>
>
> /---------Hub----------\
> | |
> | |
> vlan 100 vlan 200
> | |
> | |
> \----switch/hub--------/
>
> then that would be pretty evil
>
> >
> > Have fun! <evil grin>
> >
> > Karen E Young
> > Network Engineer
> > ELF Technologies, Inc
> > [EMAIL PROTECTED]
> >
> >
> >
> >
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