Re: Root Bridges in PVST..

Instead of a tree, what if you took 10 switches and connected them all in
parallel to each other.

SW1-SW2-SW3-SW4-Etc.etc-SW10.

You could make SW1 root of 2 VLANS that spanned all the switches and route
VLANs via SVI's or a router at SW10. It just might not be that efficient if
the two hosts your routing between both connect to SW1 :P. The L2 path would
lead all the way through 10 switches, get routed, then all the way back
through 10 switches to the destination.

I think most MLS setups usually try to pair root bridge with the L3
inter-connectivity. But theres no technical reason you couldn't do it at the
access layer or where ever your scenario happened to warrant doing it. As
long as the two vlans branch out between the hosts and the inter-vlan
router.

Spanning-tree UGH!!!! LOL

On Wed, Jun 24, 2009 at 11:10 PM, Jared Scrivener
<jscrivener_at_ipexpert.com>wrote:

> LOL. Only some of them, sometimes, fortunately.
>
>
>
> Cheers,
>
>
>
> Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
>
> Sr. Technical Instructor - IPexpert, Inc.
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>
> From: Scott Morris [mailto:smorris_at_internetworkexpert.com]
> Sent: Wednesday, 24 June 2009 10:57 PM
> To: Jared Scrivener
> Cc: 'Jitendra Anbu'; 'peter ehiwe'; 'CCIE R/S, Groupstudy'
> Subject: Re: Root Bridges in PVST..
>
>
>
> So if one light goes out, do they all go out? ;)
>
>
>
>
>
> Scott Morris, CCIEx4 (R&S/ISP-Dial/Security/Service Provider) #4713,
>
> JNCIE-M #153, JNCIS-ER, CISSP, et al.
>
> JNCI-M, JNCI-ER
>
> evil_at_ine.com
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> Jared Scrivener wrote:
>
> 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 <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 <mailto:Jitendra.Anbu_at_optus.com.au>
> <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 Thu Jun 25 2009 - 00:17:55 ART