Re: MLS QOS: 3560 vs 3550

What is the purpose of "mls qos vlan-based"?

Ed.

On Tue, Jan 26, 2010 at 2:30 AM, Jack Router <pan.router_at_gmail.com> wrote:

> "NO mls qos rewrite ip dscp" is not supported on my 3550. Command "sh mls
> qos" tells only "QoS is enabled". There is nothing about rewriting.
>
> Anyway, I am only testing this in my lab but after all there is no 3550 on
> the exam... I will concentrate on 3560 features. Thanks.
>
>
>
> From: Jules Eyabane [mailto:jep7619_at_gmail.com]
> Sent: 24-Jan-10 13:59
> To: Mark Cairns
> Cc: Jack Router; ccielab_at_groupstudy.com
> Subject: Re: MLS QOS: 3560 vs 3550
>
>
>
> Jack,
> i think i have seen this before, even with the 3560. try this:
>
> * on the 3550, issue the command :"sho mls qos". based on your config
> so far, it should display something like:
>
> * QoS is enabled (assuming you did issue "mls qos" prior)
> * QoS ip packet dscp rewrite is enabled (this is by default)
>
> the 2 bullets above mean that once you enable Qos, ,any packet traversing
> the switch will be rewritten to dscp=0. so all yo need to do to achieve
> your
> results is to just disable the global dscp rewriting, and the global
> command
> for that is "NO mls qos rewrite ip dscp". if your 3550 supports this
> command, then you should be golden. let us know what happens
>
>
> Jep.
>
> On Fri, Jan 22, 2010 at 11:54 AM, Mark Cairns <m.a.cairns_at_gmail.com>
> wrote:
>
> Are you trying to trust DSCP on the interface or are you trusting DSCP
> within the class used to define traffic for your policy? Sorry I don't have
> a 3550 in front of me. I believe you can have mls qos trust dscp on the
> interface or "trust dscp" in your class. Try the second one.
>
> Mark
> #17755, Security
>
>
> On Thu, Jan 21, 2010 at 12:23 PM, Jack Router <pan.router_at_gmail.com>
> wrote:
>
> > Responded too quickly.
> > "mls qos trust dscp" and "service-policy input TST" cannot co-exist on
> the
> > same interface. When one command is entered the other command is
> > automatically removed.
> >
> >
> > -----Original Message-----
> > From: Jack Router [mailto:pan.router_at_gmail.com]
> > Sent: 21-Jan-10 11:39
> > To: ron.wilkerson_at_gmail.com; ccielab_at_groupstudy.com
> > Subject: RE: MLS QOS: 3560 vs 3550
> >
> > Yes there is one and it works. Thanks.
> >
> > -----Original Message-----
> > From: ron.wilkerson_at_gmail.com [mailto:ron.wilkerson_at_gmail.com]
> > Sent: 21-Jan-10 11:29
> > To: Jack Router; ccielab_at_groupstudy.com
> > Subject: Re: MLS QOS: 3560 vs 3550
> >
> > Isn't there a trust dscp command on the 3550?
> > -----Original Message-----
> > From: "Jack Router" <pan.router_at_gmail.com>
> > Date: Thu, 21 Jan 2010 11:05:03
> > To: <ccielab_at_groupstudy.com>
> > Subject: MLS QOS: 3560 vs 3550
> >
> > Hello,
> >
> > I am testing policing. Here is diagram:
> >
> > R1--\
> > 3560(f0/19)----trunk----(f0/19)3550(f0/3)-----R3
> > R2--/
> >
> >
> > I am policing traffic from R1,R2 to R3
> > R1 sends packets marked DSCP 10
> > R2 sends packets marked DSCP 20
> > Policy map is applied on 3550 int f0/19:
> >
> > Policing seems to work because I can see ping drops on R1 or R2 as soon
> as
> > service policy is applied on 3550, int f0/19.
> > My problem is that 3550 rewrites all dscps to 0 as soon as mls qos is
> > enabled. On 3560 I can disable dscp rewrites with command "no mls qos
> > rewrite ip dscp" but on 3550 there is no such command.
> >
> > Is there a way not to rewrite DSCPs on 3550 so R3 will receive packets as
> > marked by R1 and R2?
> >
> > I know that there is no 3550 on the lab anymore but just want to
> understand
> > how
> > this works...
> >
> > Thanks,
> >
> >
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Received on Tue Jan 26 2010 - 15:38:15 ART