[c-nsp] ME3400 odd DSCP bit issue

[Lee Starnes]

Hi Sibbi,

>From what the customer tells me their switch is configured as such. The
issue is not that computers marking packets does not work. That seems fine.
The issue is that if the switch is the device marking the packets, we see
dscp set to "0". Since we don't have access into their 3560, I can not
verify how they have it setup, but I know that our ME3400 is using a policy
map to set dscp dscp on all packets so that we trust what is coming in from
them.

-Lee

On Mon, May 21, 2012 at 7:56 AM, Sigurbjörn Birkir Lárusson <
sigurbjornl at vodafone.is> wrote:

> You need to have mls qos trust dscp on the port on the 3560 facing the
> computer, is that in place?
>
> Kind regards,
> Sibbi
>
> On 21.5.2012 14:42, "Lee Starnes" <lee.t.starnes at gmail.com> wrote:
>
> >Hello all,
> >
> >Previously I had an issue where we were stripping the dscp bits coming
> >into
> >our switch and this was solved with the policy-map that does a set dscp
> >dscp. I can send a packet from a laptop with the bits market and see these
> >bits make it all the way through our network. However, what is happening
> >is
> >our customer is setting the dscp value on their switch and not from the
> >device sending the packets. When they do this, the bits get set to 0. If
> >they disconnect their switch and connect a laptop in place of the link to
> >them from us, they see the marked packets.
> >
> >So, my question is what causes these dscp bits to change based on the
> >customer's switch setting them and a computer setting them?
> >
> >Computer <---> 3560 <---> ME3400 (3560 sets the dscp bit and we DON'T see
> >it.)
> >Computer <---> 3560 <---> ME3400 (computer sets the dscp bit and we DO see
> >it.)
> >
> >Computer <---> 3560 <---> Computer (3560 sets the dscp bit and we see it.)
> >
> >Any insight on this would be greatly appreciated.
> >
> >Thanks,
> >
> >-Lee
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