From: Bob Sinclair (bsinclair@netmasterclass.net)
Date: Thu Jan 08 2004 - 16:09:33 GMT-3
Howard,
I don't know how I would really tell. You may be better placed to answer
this one. The verbiage in the configuration guide is:
quote:
The switch uses the per-VLAN spanning-tree plus (PVST+) protocol based on
the IEEE 802.1D standard and Cisco proprietary extensions, or it can use the
rapid per-VLAN spanning-tree plus (rapid-PVST+) protocol based on the IEEE
802.1W standard
end quote.
I guess the tricky part would be interpretation of the term "based on". In
practice, I guess we really care about interoperability. That is something
I have not looked into int detail, because I personally would never run a
brand X switch ;)
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message ----- From: "Howard C. Berkowitz" <hcb@gettcomm.com>
To: "Bob Sinclair" <bsinclair@netmasterclass.net>; "paul"
<paul_hwang@hanmail.net>
Cc: <ccielab@groupstudy.com>
Sent: Thursday, January 08, 2004 1:58 PM
Subject: Re: Uplinkfast Updated
> At 12:58 PM -0500 1/8/04, Bob Sinclair wrote:
> >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, do you know if the configuration you found and liked is the one
> that's supposed to be fully interoperable with the IEEE Rapid
> Spanning Tree, or was it still Cisco proprietary?
>
> >
> >
> >Bob Sinclair
> >CCIE #10427, CISSP, MCSE
> >www.netmasterclass.net
> >
> >----- Original Message -----
> >From: "paul" <paul_hwang@hanmail.net>
> >To: "Bob Sinclair" <bsinclair@netmasterclass.net>
> >Cc: <ccielab@groupstudy.com>
> >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" <bsinclair@netmasterclass.net>
> >> 9^4B@L : "paul" <paul_hwang@hanmail.net>, <ccielab@groupstudy.com>
> >>
> >> 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.
>
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