From: Troy Rader (troy@xxxxxxxxxx)
Date: Sat Dec 08 2001 - 13:13:38 GMT-3
Straight from CCO:
"Spanning-tree PortFast causes a port to enter the spanning-tree forwarding
state immediately, bypassing the listening and learning states."
Also...
"When you enable PortFast on a port, the port is immediately and permanently
transitioned to the spanning-tree forwarding state."
From:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat5000/rel_5_2/config/s
tp_enha.htm
I would say it is accurate to state that stp is still enabled on a port set
to portfast, but stp will NEVER block this port since it doesn't listen or
learn, but only forwards permanently.
Troy
----- Original Message -----
From: "Michael Popovich" <m.popovich@home.com>
To: "'Phil'" <ciscostudent1@yahoo.com.br>; "'Taz Kazam'"
<taz_kazam@yahoo.co.uk>; "'Rivron Francois'" <Francois.Rivron@ei-rsi.fr>;
"'thegroup'" <ccielab@groupstudy.com>
Sent: Saturday, December 08, 2001 8:47 AM
Subject: RE: Spantree Timer
> It is my understanding of the portfast command that if both ports on
> both sides are configured for portfast it will indeed immediately start
> passing packets even if there is a loop in the network. However, that is
> only temporary. I understand that the spanning tree algorithm is still
> running and after the 50 seconds it takes to run that loops will be
> detected and spanning tree will run as normal. Portfast doesn't disable
> spanning tree.
>
> MP
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Phil
> Sent: Saturday, December 08, 2001 8:16 AM
> To: Taz Kazam; Rivron Francois; thegroup
> Subject: RE: Spantree Timer
>
>
> If you have a port with portfast enabled when you connect it to another
> switch port it will be automatically placed in disable, unless that
> other port os also configured with portfast enabled (and in this case
> they will not block and a loop will occur). Phil.
>
> Taz Kazam <taz_kazam@yahoo.co.uk> escreveu: Thanks Francois
>
> I managed to find out. I think that the Cat1900 has
> the ports status set to PORTFAST by default (command: start-forwarding),
> hence, it removes the foward delay time (15+15) = 30 sec, only using
> MaxAge = 20 sec.
> If you configure the port with no start-forwarding
> i.e. disable the PORTFAST, it then takes the 50
> seconds to change over.
>
> Thanks you you reply.
>
> Taz.
>
>
> --- Rivron Francois
> wrote: > Hello,
> > my think is as the switch is able to detect a fault
> > at a physical level, the
> > port state of the redondant link is move directly to listening state.
> > So the redondant path should be on in 30s.
> >
> > Francois
> >
> > > -----Message d'origine-----
> > > De: Taz Kazam [SMTP:taz_kazam@yahoo.co.uk]
> > > Date: vendredi 7 dicembre 2001 10:38
> > > @: thegroup
> > > Objet: Spantree Timer
> > >
> > > Can anyone help.
> > >
> > > I've step up four 1900 Catalyst switch in a loop,
> > to
> > > test spanning tree. One port changes its state to
> > > blocking, as I expected, however, when I take the
> > > cable out of the non-redundant path, which cause
> > the
> > > redundant path to change from blocking to
> > fowarding -
> > > it does, but it only take 20 seconds. From my
> > reading
> > > this should take 50 seconds (15sec fwd delay -
> > 20sec
> > > MaxAge) Blocking -----15-----Listen---
> > > 15-----Learning----20------Fowarding. Im using the default factory
> > > settings!
> > >
> > > Anyone can help?
> > >
> > > Taz.
> > >
> > >
> >
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