[c-nsp] Spantree .1Q packets received on non-trunk port.

[Lee Starnes]

Thanks Mike.

Lot of great information. Thanks for taking the time to post this. Very
helpful.

-Lee


On Tue, Aug 26, 2014 at 10:56 PM, Mike Hale <eyeronic.design at gmail.com>
wrote:

> "when the handoff is an access port"
> Because I don't think it's actually configured as an access port.  The
> behavior of the interface mimics exactly what you had to configure on
> yours...that is, a trunk port with a native VLAN defined.
>
> If the configuration is what I think it is, the reason the tech's
> equipment functioned the way it did was two fold.  First, the gear
> didn't care about STP packets.  So when configured as an access port,
> the test gear sent untagged packets onto the interface which the
> upstream provider's switch put into VLAN 638 (because their interface
> had 638 configured as a native vlan).  The reason it didn't work when
> configured as a trunk is because the device didn't have the native
> vlan configured.  So it tried to send packets, tagged with VLAN 638;
> this failed because the default behavior on the Cisco gear I've worked
> with is to drop packets that are tagged with the native VLAN.
>
> "Aren't BPDU's normally part of STP's chatter?"
> Yes, but in my experience BPDUs are only sent on 'infrastructure'
> ports.  That is, ports that are trunked or have special STP settings
> applied for uplinks.  Access ports die (as the OP experienced) when
> they notice STP packets in order to prevent a loop.
>
>
> On Tue, Aug 26, 2014 at 7:55 PM, Brielle Bruns <bruns at 2mbit.com> wrote:
> > On 8/26/14 7:34 PM, Lee Starnes wrote:
> >>
> >> Thanks Mike.
> >>
> >> That took care of the problem, but still not sure why I would have to
> set
> >> the port up as a trunk port when the handoff is an access port. When the
> >> carrier tested the port, they tested it as an access port and then tried
> >> to
> >> test it as a trunk port and their test set failed when in trunk mode.
> Very
> >> odd.
> >>
> >> Anyway, thanks again.
> >>
> >
> >
> > Aren't BPDU's normally part of STP's chatter?
> >
> > I get errors like that when my MSTP instance settings are mismatched
> between
> > switches.   Perhaps its a mix of issues.
> >
> >
> > --
> > Brielle Bruns
> > The Summit Open Source Development Group
> > http://www.sosdg.org    /     http://www.ahbl.org
> >
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