From: Darby Weaver (ccie.weaver@gmail.com)
Date: Sun Sep 28 2008 - 23:10:55 ART
I think this sums it up:
For STP to operate correctly, observe certain rules when you connect PVST+
bridges to IEEE 802.1D or 802.1Q bridges. The main rule is that PVST+
bridges must connect to IEEE 802.1D or 802.1Q bridges through an IEEE 802.1Q
trunk with a consistent Native VLAN on all bridges that connect to the cloud
of IEEE 802.1Q or 802.1D bridges.
The PVST+ BPDU contains a VLAN number that allows PVST+ bridges to detect
whether the previous rule is not respected. When a Catalyst switch detects a
misconfiguration, the corresponding ports are put into a "PVID-inconsistent"
or "type-inconsistent" state, which effectively blocks the traffic in the
corresponding VLAN on a corresponding port. These states prevent forwarding
loops that misconfigurations or miswiring cause.
On Sun, Sep 28, 2008 at 9:59 PM, Darby Weaver <ccie.weaver@gmail.com> wrote:
> Have you seen this document?
>
>
>
>
> http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00801d11a0.shtml
>
>
>
> On Sun, Sep 28, 2008 at 9:12 PM, Eduardo Elizondo Elizondo <
> eduardo_elizondo@connextmx.com> wrote:
>
>> No it doesnt put it into Err-DIS, in fact, it keeps in up/up state, its
>> weird
>>
>>
>>
>> From: Pavel Bykov [mailto:slidersv@gmail.com]
>> Sent: domingo, 28 de septiembre de 2008 04:50 p.m.
>> To: Eduardo Elizondo Elizondo
>> Cc: ccielab@groupstudy.com
>> Subject: Re: Spanning-tree LBK state
>>
>>
>>
>> I know that it often appears when Cisco Phones are not powered by inline
>> power and there is power outage, so switch and phone power up
>> independently...
>>
>> I'd guess that LBK is a state when SW sees it's own BPDU. But that's
>> just a guess. I know it will generate Err-DIS by default.
>>
>>
>>
>> On Sun, Sep 28, 2008 at 7:34 PM, Eduardo Elizondo Elizondo
>> <eduardo_elizondo@connextmx.com> wrote:
>>
>> Hi guys,
>>
>> Somebody have some documentation about Spanning-tree LBK (Loopback)
>> state?
>>
>> Sts
>> Spanning-tree states; valid values are BKN* (broken)1 , BLK (blocking),
>> DWN (down), LTN (listening), LBK (loopback), LRN (learning), and FWD
>> (forwarding).
>>
>> Best Regards!!
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
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>>
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>>
>>
>>
>>
>>
>>
>>
>> --
>> Pavel Bykov
>> -------------------------------------------------
>> Stop the braindumps!
>> http://www.stopbraindumps.com/
>>
>>
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>> _______________________________________________________________________
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