Re: VLAN based QoS

Thanks Joe!

On Thu, May 13, 2010 at 9:50 PM, Joe Astorino <jastorino_at_ipexpert.com>wrote:

> Well, what Eseosa is saying is certainly true. However, you don't
> HAVE to trust anything. If the task did not state to trust DSCP I
> don't see a reason to have that statement there. If you mark DSCP for
> one class of traffic (say HTTP) that does not imply that you MUST
> trust DSCP for everything else.
>
> Also, don't forget to apply "mls qos vlan-based" on your interfaces : )
>
> On Thu, May 13, 2010 at 8:18 AM, hopalong <ccieangel2_at_googlemail.com>
> wrote:
> > Thank you, so if you change the dscp for one type of traffic, you have to
> > have the trust statement for the class default. OK, but still not
> > understanding why that should be true when you have defined the only
> traffic
> > you want to change? Any idea or just one of those cisco things?!
> >
> > On Thu, May 13, 2010 at 12:46 PM, eseosa <eseosa.ehiwe_at_gmail.com> wrote:
> >
> >> Yes, trust dscp implies that you are trusting the dscp marking "on
> >> any traffic coming from any device on that vlan (i.e class
> >> class-default) " but for http traffic coming from any webserver on
> >> that vlan you are overriding or setting the dscp marking to what you
> >> have specified.
> >>
> >>
> >> HTH
> >>
> >>
> >>
> >> On 5/13/10, hopalong <ccieangel2_at_googlemail.com> wrote:
> >> > Hi
> >> >
> >> > I am configuring VLAN based QoS on a catalyst switch.
> >> >
> >> > I have matched the traffic thus:
> >> >
> >> > ip access-list extended HTTP
> >> > permit tcp any eq 80 any
> >> > !
> >> > class-map HTTP
> >> > match access-group name HTTP
> >> >
> >> > and then I need to change the dscp value:
> >> >
> >> > policy-map VLAN46
> >> > class HTTP
> >> > set dscp 16
> >> >
> >> > and then apply:
> >> >
> >> > interface vlan 46
> >> > service-policy input VLAN46
> >> >
> >> > My question is that the solution provided has an additional line in
> the
> >> > class-map HTTP which reads:-
> >> >
> >> > class class-default
> >> > trust dscp
> >> >
> >> > is this strictly necessary to the solution ?
> >> > Thanks for reading!
> >> >
> >> >
> >> > Blogs and organic groups at http://www.ccie.net
> >> >
> >> >
> _______________________________________________________________________
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> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >>
> >>
> >> --
> >> Warm Regards,
> >>
> >> Eseosa
> >> CCIE #23782
> >> Before God we are all equally wise - and equally foolish.
> >> Albert Einstein
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
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> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
> --
> Regards,
>
>
>
> Joe Astorino - CCIE #24347
> Sr. Technical Instructor - IPexpert
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Received on Fri May 14 2010 - 14:47:41 ART