From: paul (paul_hwang@hanmail.net)
Date: Thu Jan 08 2004 - 15:51:45 GMT-3
Appreciate for your prompt reply. cleared everything !!
someone out there can point us to some documentation on this uplinkfast
enhancement.
Cheers,
Paul.
---------[ 9^@: 8^@O 3;?k ]----------
A&8q : Re: [RE]Uplinkfast Updated
3/B% : Thu, 8 Jan 2004 13:40:40 -0500
:83=@L : "Bob Sinclair" <bsinclair@netmasterclass.net>
9^4B@L : "paul" <paul_hwang@hanmail.net>
Paul,
I think you've got it. Uplinkfast goes with Cisco PVST+ mode. The
Rapid-PVST+ mode includes enhancements that make uplinkfast unnecessary.
My 3550s are running: c3550-i5q3l2-mz.121-14.EA1.bin
My guess is that any Cisco switch will do this rapid fail-back uplinkfast
if that switch also offers rapid-pvst mode as an option, but I would be
very interested if someone out there can point me to some documentation
on this uplinkfast enhancement.
Stay cool,
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: paul
To: Bob Sinclair
Sent: Thursday, January 08, 2004 1:30 PM
Subject: [RE]Uplinkfast Updated
Thanks again Bob.
Could I make correct understanding.
First, I understand the uplinkfast is used for PVST+ not for the
rapid-PVST+.
If so, even with the PVST+ not rapid-PVST+, the uplinkfast can make the
failback quickly with just missing of 1-2 pings. If yes, could you let me
know your IOS version on the Cat3550's so I can make test as well.
Of course, I believe that the rapid-PVST+ should work on both quickly.
Am I missing anything?
Cheers,
Paul.
---------[ k0쏆? k)붿씪 ?4l슜 ]----------
?쒕*) : Uplinkfast Updated
?좎쭨 : Thu, 8 Jan 2004 12:58:25 -0500
k34k궦??: "Bob Sinclair"
k0쏅뒗??: "paul"
?(j퍡k0쏅뒗??:
Paul,
I just labbed up the Uplinkfast and rapid-pvst approaches on 3 3550s to
verify the performance we talked about earlier. I found that Uplinkfast
by
itself now gives rapid fail-back, without the need to go all the way to
rapid-pvst mode.
The rapid-pvst+ worked great in both directions - missed just a ping or
two.
But uplinkfast by itself gave about the same performance, and I believe
this
is a change. When the access switch tried to fail-back to the original
root
port, it held the original root port in blocking throughout the normal
listening and learning phases. It then quickly shut the backup root and
put
the original root in forwarding, so I only lost a ping or two.
This is not your grandfather's uplinkfast! It used to close the backup
root and then wait for the original to go through listening and learning.
Perhaps an enhancement that came with rapid-pvst capabilities?
Bottom line - if you have the perfect access-distribution-distribution
triangle and you can use uplinkfast on the access switch, you should get
very fast fail-back as well as fail-over on recent Cisco switches.
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: "paul"
To: "Bob Sinclair"
Cc:
Sent: Thursday, January 08, 2004 12:36 PM
Subject: [RE]Re: hsrp and stp (how to avoid second outage)
> Hi Bob,
>
> Thanks for clear explanation.
>
> Anyone deployed the rapid-PVST+ in production, how about this stability
> compared with the PVST+. Any bad experience?
>
> Cheers,
>
> Paul.
>
> ---------[ 9^@: 8^@O 3;?k ]----------
> A&8q : Re: hsrp and stp (how to avoid second outage)
> 3/B% : Thu, 8 Jan 2004 11:51:21 -0500
> :83=@L : "Bob Sinclair"
> 9^4B@L : "paul" ,
>
> Paul,
>
> AFAIK, there is no comparable "preempt/no preempt" feature int STP.
> Of course, you could manally raise the priority of the old root bridge
> before
> restoring it if the outage scenario allows (an IOS upgrade, for
> example).
>
> You are right to be concerned about the "fail-back" delay. If you run
> Uplinkfast on your access switches, for example, then you will get
> 1-2 second failover to the new root port if the root bridge fails. But
> when the root bridge comes back you will have a 30-second outage as the
active
> root port immediately closes and the new root port goes through
listening
> and learning.
>
> You could speed this up by tweaking the timers, or you could consider
> rapid-pvst+ if all your switches support it.
>
> Bob Sinclair
> CCIE #10427, CISSP, MCSE
> www.netmasterclass.net
>
> ----- Original Message -----
> From: "paul"
> To:
> Sent: Thursday, January 08, 2004 10:52 AM
> Subject: hsrp and stp (how to avoid second outage)
>
> > HI all,
> >
> > Assuming that configured the HSRP and STP on the active and standby
> > distribution switches.
> >
> > In case of HSRP, we can use the preemt option to return to the
> original
> > primary switch once the primary switch recovered. That is, without
> the
> > preemp option, secondary switch keeps active continually after the
> > primary fails.
> >
> > Wondering how about the STP.
> >
> > I configured the PVST+ between Cat6500 and Cat4000 switches.
> >
> > If the root bridge fails, secondary root bridge will take over to
> active.
> >
> > And then, what happen after the original primary swith recovered. I
> > understand the original primary switch will regain the root bridge.
> That
> > is, it will bring sencond outage as the HSRP preempt option do.
> Then how
> > can configure the switch so the secondary root bridge keeps the
> active
> > though the original primary returned.
> >
> > TIA,
> >
> > Paul.
> >
> >
"?l8. @NEM3], Daum" http://www.daum.net !:Fr;}>24B 9+7a GQ8^@O3]!;
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