RE: Root Bridges in PVST..

The post below isn't entirely accurate.

Intra-vlan traffic will flow towards the root bridge only if switches are on
either side of the root bridge. If they are on the same side then traffic
will flow directly between them.

Imagine the switch STP domain like a Christmas tree where the root bridge is
the star at the top and all other switches are ornaments on one side or
another (per-VLAN in MST, PVST or Rapid-PVST). To get from one ornament to
another you can either go down or up your side of the tree depending on
where your destination happens to be. The only thing you can't do is go
across the bottom of the tree, because that's where STP is blocking or
discarding (and where ornaments fall off). I hope that helps, Jitendra.

Cheers,
 
Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
Sr. Technical Instructor - IPexpert, Inc.
URL: http://www.IPexpert.com
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
Mailto: jscrivener_at_ipexpert.com

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
Jitendra Anbu
Sent: Wednesday, 24 June 2009 8:31 PM
To: 'peter ehiwe'
Cc: CCIE R/S, Groupstudy
Subject: RE: Root Bridges in PVST..

Thanks Peter, I am still trying to get my head around this one. My
understanding was regardless on the VLAN connectivity; all layer 2 traffic
will traverse the RB.

Which sounds kinda of inefficient, because if you have a large network of
say 50 switches & one RB. But, if you split between a few a few RBs based on
the VLANs this does not sound that bad.

Thanks again.
---------------------------------------------------------
Regards,

Jit

-----Original Message-----
From: peter ehiwe [mailto:ccie.in.nigeria_at_gmail.com]
Sent: Thursday, 25 June 2009 4:06 AM
To: Jitendra Anbu
Cc: CCIE R/S, Groupstudy
Subject: Re: Root Bridges in PVST..

Intra vlan traffic can go thru the root bridge depending on were
clients assigned to the vlan in question are located , if the clients
communicating span multiple switches that make up the spanning tree
topology then intra vlan traffic has to flow thru the root bridge for
the hosts to communicate the same goes for mst.

HTH

Regards,

Peter

On 6/24/09, Jitendra Anbu <Jitendra.Anbu_at_optus.com.au> wrote:
> Hi there,
>
> Can someone explain ., if switches are running PVST, would INTRA-VLAN
> communication need to go through the root bridge? How would this differ in
> MST?
>
> Thanks,
>
> Jit
>
>
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Received on Wed Jun 24 2009 - 22:49:03 ART