RE: Root Guard

If the original root bridge is still a root bridge, then root guard has
done its job. To do that it has isolated the second switch from the
original network. you will see that devices connected to Switch 1 cannot
communicate with Switch 2 (assuming root guard has been configured
consistently).

I do not see how that would cause a loop, since they are in different
broadcast domains.

The basic application of root guard is in a data center environment, where
you want to make sure that a customer switch does not become the root for
the provider network. To accomplish this, the provider switch isolates the
offending customer switch from the switched network. If that customer
switch becomes the root in its own, isolated network, then that is OK with
the provider.

HTH,

Bob Sinclair

From: Abiola Jewoola [mailto:biola_y2k_at_yahoo.com]
Sent: Friday, June 04, 2010 11:04 AM
To: bob_at_bobsinclair.net
Cc: ccielab_at_groupstudy.com
Subject: RE: Root Guard

Sorry I dont fully understand your explanation.

yea the switches are now claiming to be the root for a particular vlan.

But if the idea was to protect the real root bridge from loosing its
status.and if the root inconsistent state segments the switches and each of
them are claiming to be the root. wont that cause a loop?

--- On Fri, 6/4/10, Bob Sinclair <bob_at_bobsinclair.net> wrote:

From: Bob Sinclair <bob_at_bobsinclair.net>
Subject: RE: Root Guard
To: "'Abiola Jewoola'" <biola_y2k_at_yahoo.com>, ccielab_at_groupstudy.com
Date: Friday, June 4, 2010, 7:20 AM

Hello Abiola,

This is the intended operation of the root guard feature. The root
inconsistent state serves to segment the broadcast domain, isolating the
switches from each other. You should see that both switches are now root,
each for its own broadcast domain.

HTH,

Bob Sinclair

> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Abiola Jewoola
> Sent: Friday, June 04, 2010 10:00 AM
> To: ccielab_at_groupstudy.com
> Subject: Root Guard
>
> Hello GS
>
> I am trying to configure rootguard.
>
> Here is the scenario.
>
> I have have four switches and one of them is the root bridge because it
> has
> the lowest bridge ID. I want to configure root guard so that the root
> bridge
> does not loose its status even if there is a better priority from other
> switches in the domain.
>
> I applied the spanning-tree guard root command on the interface
> connecting to
> the other switches on the. As i changed the priority on one of the
> other
> switches it became the root bridge,
>
> The port which had the rootguard command went to inconsistent mode. But
> it did
> not stop the other switch from taking over as the root bridge.
>
> i need some explanation plssss
>
> Regards
>
>
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Received on Fri Jun 04 2010 - 11:17:00 ART