Re: STP Timer values on the secondary bridge

Hi Mohammed,

  Got it and thank you very much for the explaination

Regards
Anantha Subramanian Natarajan

On Sat, Sep 5, 2009 at 9:41 AM, Mohamed El Henawy <m.henawy_at_link.net> wrote:

> Hello Anantha ,
>
> these timers are not really used with RSTP Switch doesnt wait for the
> timers. the only time we might need them is when we connect switch runing
> RSTP with another bridge runing STP.
>
> ..as per cisco
>
> RSTP (IEEE 802.1w) natively includes most of the Cisco proprietary
> enhancements to the 802.1D spanning tree, such as BackboneFast, UplinkFast,
> and PortFast. RSTP can achieve much faster convergence in a properly
> configured network, sometimes in the order of a few hundred milliseconds.
> Classic 802.1D timers, such as forward delay and max_age, are only used as a
> backup and should not be necessary if point-to-point links and edge ports
> are properly identified and set by the administrator. Also, the timers
> should not be necessary if there is no interaction with legacy bridges.
>
>
> http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cfa.shtml
>
>
>
>
>
>
> ----- Original Message -----
> *From:* Anantha Subramanian Natarajan <anantha.natarajan_at_gravitant.com>
> *To:* Mohamed El Henawy <m.henawy_at_link.net> ; Cisco certification<ccielab_at_groupstudy.com>
> *Sent:* Saturday, September 05, 2009 6:13 PM
> *Subject:* Re: STP Timer values on the secondary bridge
>
> Hi Mohammed,
>
> Atleast I am not sure whether it is right or wrong ...But with
> my understanding,it make logical that all the switches in the Rapid
> Spanning-Tree protocol participate in providing topology informations to
> others via BPDUs,which is different from 802.1d,where Root switch alone
> sends periodic BPDUs down the tree and so assuming that is the
> characteristics,it sounds right for me that in case of Rapid SPT all the
> bridges/switches in that doamin needs to be configured with the timer values
> for consistency.
>
> Obviously would like to hear expert comment on his question and also
> correcting my understanding is wrong
>
> Thanks for the help
>
> Regards
> Anantha Subramanian Natarajan
>
> On Sat, Sep 5, 2009 at 6:52 AM, Mohamed El Henawy <m.henawy_at_link.net>wrote:
>
>> I think if this is Rapid SPT we need to modify it on all Switches....Right
>> or Wrong ??
>>
>>
>>
>>
>> ----- Original Message ----- From: "Anantha Subramanian Natarajan" <
>> anantha.natarajan_at_gravitant.com>
>> To: "Cisco certification" <ccielab_at_groupstudy.com>
>> Sent: Saturday, September 05, 2009 4:07 AM
>> Subject: STP Timer values on the secondary bridge
>>
>>
>> Hi All,
>>>
>>> I was going through spanning tree protocol and here by referencing the
>>> below paragraph read
>>>
>>> "You can only modify the timer values from the root bridge.Modifying the
>>> values on other bridges has no effect.However,don't forget to update any
>>> "backup" root bridges "
>>>
>>> My question is ,if for example in the real lab they give a task to
>>> configure
>>> SW1 has primary root for vlan x and SW2 has secondary root for Vlan x and
>>> then in another task,if they ask to change the forward-delay timer value
>>> to
>>> y seconds for Vlan x,do we have to configure this on both root primary
>>> and
>>> secondary switch.I heard many times that we don't neeed to worry about
>>> redundancy unless specifically asked in the lab.But just want to make
>>> sure,if they ask the above task,can we just configure the timer value on
>>> the
>>> root primary and not on the secondary.
>>>
>>> Kindly clarify the same.Thanks for the help
>>>
>>> Regards
>>> Anantha Subramanian Natarajan
>>>
>>>
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>>>
>>
>>
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Received on Sat Sep 05 2009 - 10:51:37 ART