From: Tshon (tshon@xxxxxxxxxxx)
Date: Fri Mar 01 2002 - 21:11:54 GMT-3
Last but not least, make sure you set the backup root to a value one
higher than the current root. If not and you
leave this up to the bridges mac addresses you could be using sub
optimal paths. So, a couple of suggestions::
If you have more than one vlan.... I hope..... then set root and
backup roots and posibily and backup to the backup
priority 0
priority 1
priority 2
per vlan is really important, you could also load balance by making the
backup the root for some vlans.
Joseph Ezerski wrote:
>AH yes, I read the question wrong. He was attempting to make it so a switch
>could NOT become root. My bad. So, to clear up confusion, what I wrote is
>the explanation to make a switch the definitive root bridge. So sorry for
>the misread on my part.
>
>-Joe
>
>-----Original Message-----
>From: Przemyslaw Karwasiecki [mailto:karwas@ifxcorp.com]
>Sent: Friday, March 01, 2002 12:19 PM
>To: Joseph Ezerski
>Cc: 'alain faure'; 'Leigh Anne Chisholm'; 'Clark J';
>ccielab@groupstudy.com
>Subject: RE: a question on SPANTREE
>
>
>Joseph,
>
>This statement is taken vaebatim from CCO:
>
>"The switch with the highest bridge priority (the lowest numerical
> priority value) is elected as the root switch. If all switches are
> configured with the default priority (32768), the switch with the
> lowest MAC address in the Layer 2 network becomes the root switch"
>
>Here:
>http://www.cisco.com/univercd/cc/td/doc/product/lan/cat5000/rel_6_3/config/s
>pantree.htm#xtocid129753
>(beware wrap)
>
>According to this priority 0 will garantee that switch will
>become root, because it is lowest numerical priority value.
>
>I understand that I am missing something, as you sound
>very confident in your statement, which is contradictory
>to CCO. Can you please clarify a bit more?
>
>Thank you,
>
>Przemek
>
>On Fri, 2002-03-01 at 14:47, Joseph Ezerski wrote:
>
>>Alain, I am assuming that you only have one vlan? The command you entered
>>here will set the spantree priority first to 0, then back to 65535 but
>>
>only
>
>>for VLAN 1.
>>
>>Try this instead:
>>
>>set spantree priority 0 <vlan #>
>>
>>Do that for every vlan you have but only on the root bridge. Leave every
>>other switch the default. Note that you stand a good chance of seeing a
>>major recovergence if you are entering that command on the switch that is
>>not currently the root.
>>
>>That will work. I am 100% sure.
>>
>>Forget about root guard for now. Spantree Priority 0 protects you from
>>about 99.999% of anything else becoming the root.
>>
>>-Joe
>>
>>-----Original Message-----
>>From: alain faure [mailto:alainfaure@yahoo.fr]
>>Sent: Friday, March 01, 2002 11:30 AM
>>To: jezerski@broadcom.com; 'Leigh Anne Chisholm'; 'Clark J';
>>ccielab@groupstudy.com
>>Subject: RE: a question on SPANTREE
>>
>>
>>hi,
>>
>>to solve the problem with another way i try :
>>- set spantree priority 0
>>- set spantree priority 65535
>>- set spantree guard root 4/28 (one port of my catalyst)
>>
>>Without success, any comments ?
>>
>>Best regards
>>
>> --- Joseph Ezerski <jezerski@broadcom.com> a icrit : > If you want to get
>>really advanced and you have bigger switches, like the
>>
>>>Cat6509, look into the root guard feature.
>>>
>>>-Joe
>>>
>>>-----Original Message-----
>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>>>Leigh Anne Chisholm
>>>Sent: Friday, March 01, 2002 10:34 AM
>>>To: alain faure; Clark J; ccielab@groupstudy.com; clark.j@163.com
>>>Subject: RE: a question on SPANTREE
>>>
>>>
>>>That's a drastic response to what is actually a simple problem. In
>>>implementing that solution, you're creating the potential for problems
>>>
>>well
>>
>>>beyond those that you want to resolve. Spanning Tree has a simple
>>>
>>priority
>>
>>>system that's easy to manipulate that doesn't have the implications of
>>>
>>your
>>
>>>solution.
>>>
>>>Check the CCNA curriculum for information on how to configure a switch
>>>
>so
>
>>>that
>>>it can't become the root switch in any given VLAN.
>>>
>>>
>>> -- Leigh Anne
>>>
>>>-----Original Message-----
>>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>>>alain faure
>>>Sent: Friday, March 01, 2002 11:23 AM
>>>To: Clark J; ccielab@groupstudy.com
>>>Subject: Re: a question on SPANTREE
>>>
>>>
>>>hi,
>>>
>>>that's interresting question, and we have a long debate on this with
>>>
>some
>
>>of
>>
>>>my
>>>friends about one of our customer site.
>>>
>>>for me, i think the better way (but they don't agree with me) is to
>>>
>>disable
>>
>>>spanning tree on the VLAN for the switch you don't want they become root
>>>
>?
>
>>>What
>>>do you think about ?
>>>
>>>best regards
>>>
>>>
>>> --- Clark J <clark.j@163.com> a icrit : > Dear CCIEs and Near CCIEs,
>>>
>>>> How to configure a switch so that it can't become the root switch in
>>>>
>>>VLAN
>>>A
>>>
>>>>?
>>>>Best regards,
>>>>Clarke J
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