Re: Bpdu issues

Access ports send BPDU's, the only way to get an interface to stop
sending BPDU's is to enable BPDUFILTER or disable STP.

You will use both features when you want to stop sending BPDU's and
also get the interface to go err-disabled when a BPDU is received. The
BPDUFILTER feature must be enabled globally for this to work,
otherwise if you enable it on the interface the BDUGUARD feature is
not triggered due to BPDUFILTER.

Example config of the two features; this config will stop bpdu's from
being sent and also cause the interface to err-disable if a bpdu is
received:

spanning-tree portfast bpdufilter default
spanning-tree portfast bpduguard default

or

spanning-tree portfast bpdufilter default
int fa0/1
 spanning-tree bpduguard enable

I didn't have time to lab this, but I am reasonably confident that it
works in this way.

Jason

On 22 September 2010 21:31, Dr.Fleming <doctorfleming_at_gmail.com> wrote:
> Hi Mustafa!!
>
> I enabled both features just to check what the result would be.
> When a BPDU came into the access-port, the port went to err-disable, so the
> BPDU Guard feature wins.
>
> I'm not sure if it's useful to enable both features in global config. BPDU
> Filter stops sending BPDUs (but and access-port doesnt send BPDUs anyway)
> and make the port loose its portfast condition if it receives a BPDU.
> On the other hand, BPDU Guard doesnt make a port to stop sending BPDUs
> (doesnt matter when the port is an access-port, because it already doesnt
> send them) but it makes the port to shut down if it receives a BPDU.
>
> So, why to enable both features in global config?? I would config only BPDU
> Guard.
>
> Experts, do you see any reason to do it??
>
>
>
> On Mon, Sep 20, 2010 at 4:38 PM, karim jamali <karim.jamali_at_gmail.com>wrote:
>
>> Hi Mustafa,
>>
>> I am not sure who will "win" but logically I can't seem to find any reason
>> to do so unless a crazy CCIE task is trying to go that way. Note that
>> bpdufilter acts both ways and it stops sending/receiving of BPDUs. BPDU
>> guard as per my knowledge only acts in one direction and the action it
>> takes
>> is put a port in err-disabled state if it receives a BPDU.
>>
>> Best Regards,
>>
>> 2010/9/20 Mustafa Yadav <mustafa.yadav_at_gmail.com>
>>
>> > Hi
>> > Can we enable bpdu filter default and bpduguard at the same time in
>> global.
>> > What will be the effect of this.any bpdy transmit or in the case of
>> > bpdu receieved what happens
>> >
>> > --
>> > Mobil cihaz}mdan gvnderildi
>> >
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>> KJ
>>
>>
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Received on Wed Sep 22 2010 - 21:44:32 ART