Re: Spanning-tree link-type point-to-point or portfast trunk

Follow up question on this...

Per cisco:

*"RSTP can only achieve rapid transition to the forwarding state on edge
ports and on point-to-point links. The link type is automatically derived
from the duplex mode of a port. A port that operates in full-duplex is
assumed to be point-to-point, while a half-duplex port is considered as a
shared port by default. This automatic link type setting can be overridden
by explicit configuration. In switched networks today, most links operate in
full-duplex mode and are treated as point-to-point links by RSTP. This makes
them candidates for rapid transition to the forwarding state. "*

Anyone have any details on what happens to rapidly transition the port to
forwarding when RSTP determines it's a PTP link (either via auto detection
of duplex or via hardcoding it)?

Well, I guess my real question is - is its effect redundant to
"spanning-tree portfast" or "spanning-tree portfast trunk"... One being a
part of 802.1w and one being a cisco addon to 802.1d (portfast). Or do they
work differently.

Chris

On Wed, May 13, 2009 at 3:45 PM, Jared Scrivener <jscrivener_at_ipexpert.com>wrote:

> The first command defines the link as a p-to-p link from the perspective of
> Rapid-PVST+.
>
> The second command is used to enable portfast on a trunk: only do this
> towards edge switches that have bpduguard enabled so that you do not risk
> creating an STP loop.
>
> Cheers,
>
> Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
> Sr. Technical Instructor - IPexpert, Inc.
> 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
> Rene
> Sent: Wednesday, 13 May 2009 2:38 PM
> To: Amarnath Mamidi
> Subject: Spanning-tree link-type point-to-point or portfast trunk
>
> HI folks,
>
> just playing arround with spanning-tree,
>
> can someone declare what the differents between the interface cmd
> "spanning-tree link-type point-to-point" and "spanning-tree portfast trunk"
> is ?
>
> cheers Reni
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Wed May 13 2009 - 21:44:45 ART