From: Guyler, Rik (rguyler@shp-dayton.org)
Date: Wed Oct 26 2005 - 09:14:54 GMT-3
The Forward Delay timers designate the time frame for the Listening and
Learning states (15 seconds each by default). The max-age timer designates
the time the initial BPDU is stored (20 seconds by default) while waiting
for other BPDU's. If a consistent flow of the same BPDU is received then
once the 20 second timer expires the port will transition into the
forwarding state. This has nothing to do with aging out MACs in the
CAM/MAC-address table, although there is an aging timer for that as well,
just not this one when we are talking STP. Obviously these are default
values and can be modified either directly or indirectly with the use of
portfast, uplinkfast, backbonefast, etc.
I agree I have not heard of a "reconfiguration" stage but it may just be a
matter of syntax.
Rik
-----Original Message-----
From: Niche [mailto:jackyliu419@gmail.com]
Sent: Tuesday, October 25, 2005 9:38 AM
To: simon hart
Cc: Javier Tomi; ccielab@groupstudy.com
Subject: Re: STP Question
Hi guys,
May be I will wait for abit and see any input from others before I say
anything again.
As far as I know, 15+15+20 = 50, that's how "STP 50 seconds rule" come from,
just a thought =)
Cheers~
Jacky
On 10/25/05, simon hart <simon@harttel.com> wrote:
>
> Niche,
>
> I have never heard of reconfiguration stage?
>
> The max-age timer is for aging out macs in the cam prior to going to
> listening or learning. Now if the port is coming up from first
> initialisation the port will only go through the learning and
> listening mode Hence 8 +8 = 16
>
> If the port is reconverging then you have to wait for the cam to age
> out with the max-age timer and this will need to add the max-age, thus
> an addtional 6 seconds int the example given.
>
> So the point of my earlier mail was it depends upon what state the
> port is in to begin with
>
> Simon
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Niche
> Sent: 25 October 2005 13:14
> To: Javier Tomi
> Cc: ccielab@groupstudy.com
> Subject: Re: STP Question
>
>
> Hi guys,
>
> To Simon,
>
> According to software configuration guide of 3550
>
> Forward-delay timer - Determines how long each of the listening and
> learning states last before the interface begins forwarding.
> So if we set 7 or 8, then that will make the total delay time to 20 or
> 21 seconds, listen stage - 7 seconds (forward-delay) learning stage -
> 7 seconds (forward-delay) reconfiguration stage - 6 seconds (max-age)
>
> To Javier,
>
> Honestly, I would like to clarify the original question as well cause
> I am still trying to figure out the accurate requirement of it. But
> snapshot routing can be used not only just dial-up link I think.
>
> Cheers~
> Jacky
>
> On 10/25/05, Javier Tomi <fjtm@tid.es> wrote:
> >
> > Hi Jacky,
> >
> > I am not sure to understand your question... Snapshot routing is
> > used to periodically trigger conections on dial up environments to
> > make sure that the routing table is accurate. I don't think that
> > this is what you are looking for.
> >
> > Could you try to clarify the requirements...
> >
> > Regards
> >
> > Javi
> >
> >
> > Niche wrote:
> >
> > >Sorry to make some modification to my previous post,
> > >
> > >1 router be (active router speaker) and 1 router be (listener &
> re-active
> > >route speaker)
> > >
> > >Cheers~
> > >Jacky
> > >
> > >On 10/25/05, Niche <jackyliu419@gmail.com> wrote:
> > >
> > >
> > >>1. So I guess the configuration is,
> > >>
> > >>spanning-tree vlan x forward-time 4 spanning-tree vlan x max-age 6
> > >>
> > >>2. Sorry in advance if it's due to my understanding to the
> > >>original question is wrong.
> > >>
> > >>ip rip triggered
> > >>
> > >>this command is actually make the router send update to it's
> > >>neighbor
> > when
> > >>there is a change in network topology.
> > >>
> > >>I think that's not the original question ask for? Snapshot routing
> > >>was also the answer that pop up in my mind cause the question was
> > >>asking
> > kinda
> > >>like 1 router be route speaker and 1 router be route listener.
> > >>
> > >>May be I am wrong?
> > >>
> > >>Cheers~
> > >>Jacky
> > >>
> > >>On 10/25/05, Javier Tomi <fjtm@tid.es> wrote:
> > >>
> > >>
> > >>>1. Tunning the STP timers. Remember to do it on the STP root and
> backup
> > >>>root of the VLAN
> > >>>2. Ip rip triggered at interface level
> > >>>
> > >>>HTH
> > >>>
> > >>>Javi
> > >>>
> > >>>Nadeem Zahid (iszahid) wrote:
> > >>>
> > >>>
> > >>>
> > >>>>1. Let say I want to move a switchport into FWD state under 16
> second
> > >>>>and yet it should
> > >>>>go through all STP states, what comes to your mind?
> > >>>>- Portfast? will only go through all states after a switch
> > >>>>resets, otherwise will skip 2 states
> > >>>>- Tune down the STP timers to minimum for that VLAN?
> > >>>>LIS=4+LRN=4+AGE=6
> > >>>>Which one sounds better fit to fulfill the requirement?
> > >>>>
> > >>>>2. R1--------------R2
> > >>>>- R1 should only send RIP update when it sees one, otherwise not.
> > >>>>What comes to your mind - Snapshot?
> > >>>>
> > >>>>thanks
> > >>>>
> > >>>>Nadeem
> > >>>>
> > >>>>NADEEM ZAHID
> > >>>>Cat6500 MPLS & FM DevTest
> > >>>>
> > >>>>250 West Tasman Drive
> > >>>>San Jose, CA-95134 USA
> > >>>>IP Phone: 1 (408) 526 5857
> > >>>>IP Fax: 1 (408) 527 1325
> > >>>>
> > >>>>"Life is short - use it...!"
> > >>>>
> >
> >
>
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