Re: OT: Catalys 6500 qos policing doubts

>>>the 6k line is a complicated beast. QoS
'Carlos is correct !!!
Please list all the modules (northbound and southbound) that tou hve for
cooking. QoS varies on modular to module.

-frog

On Tuesday, May 22, 2012, Carlos G Mendioroz wrote:

> Juan,
> the 6k line is a complicated beast. QoS is done at several places, and it
> is an evolving architecture.
>
> That said, the page your are referring seems to address PFC QoS, i.e., QoS
> implemented by the policy feature card at a global stage.
> (As opposed to line card QoS)
>
> This same page says:
>
> You can classify and apply QoS (for example, marking) and then, on
> another interface or network device, classify again based on the
> marked value and apply other QoS.
>
> The "markdown DSCP" is (I'm interpreting the doc now, i.e., I'm not
> talking from experience but from an educated interpretation) a rewrite of
> the incoming DSCP based on policing. (That is, if you exceed some limit,
> then transmit and remark).
>
> The way I read the document, it means that the remarking of a given
> internal DSCP is global. That is, if an exceed clause remarks AF31 into
> AF43, it has to do so everywhere and you can not remark AF31 into AF41
> elsewhere in the same chasis.
>
> There is another interesting note:
>
> When you apply both ingress policing and egress policing to the same
> traffic, both the input policy and the output policy must either mark
> down traffic or drop traffic. PFC QoS does not support ingress
> markdown with egress drop or ingress drop with egress markdown.
>
> which might make sense because PFC logic is applied once in the packet
> flow, not twice, and somehow combining a drop with a remark is not
> supported.
>
> Hope this makes sense. Or else, causes someone with more info to speak up
> :)
>
> Also, I've found lots of useful QoS information in cisco's medianet design
> pages, at http://www.cisco.com/en/US/**docs/solutions/Enterprise/**
> Video/Medianet_Ref_Gd/**medianet_ref_gd.html<http://www.cisco.com/en/US/docs/solutions/Enterprise/Video/Medianet_Ref_Gd/medianet_ref_gd.html>and
> http://www.cisco.com/en/US/**docs/solutions/Enterprise/WAN_**
> and_MAN/QoS_SRND_40/QoSWAN_40.**html<http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSWAN_40.html>
>
> -Carlos
>
>
> Juan @ 21/05/2012 18:37 -0300 dixit:
>
>> Carlos, maybe i am misunderstanding the 15.0.1 IOS for 6500 config notes
>> , but at:
>> http://www.cisco.com/en/US/**docs/switches/lan/**catalyst6500/ios/15.0SY/
>> **configuration/guide/qos_class_**mark_police.html<http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/15.0SY/configuration/guide/qos_class_mark_police.html>
>> you can see this note at "Overview of Policing":
>>
>> "For all policers, PFC QoS uses a configurable global table that maps
>> the internal DSCP value to a marked-down DSCP value. When markdown
>> occurs, PFC QoS gets the marked-down DSCP value from the table. You
>> cannot specify marked-down DSCP values in individual policers."
>>
>> I am trying to do this:
>> -mark some types of traffic entering Cat6500 layer 2 interfaces using
>> different DSCP values
>> -policing these same flows previously marked at a different output
>> interface (layer 3 interface of the same 6500) , by matching them
>> using dscp values "assigned" on the input. Then, i do not see clearly if
>> the comment "You cannot specify marked-down DSCP values in individual
>> policers." is a restriction for this type of config (i have done a SPAN
>> of the output traffic, and i can not see the new dscp values... maybe
>> this is normal because the dscp assigned at the input is only an
>> "internal dscp" ??)
>> Many thanks newly & Best Regards
>>
>>
>> 2012/5/21 Carlos G Mendioroz <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>
>>
>> Where did you read that ?
>> AFAIK, you can mark on input and do congestion management on output
>> even on a 6k.
>> -Carlos
>>
>> JuanF @ 21/05/2012 15:40 -0300 dixit:
>>
>> Hi all,
>>
>> I have a 6509 Catalyst with:
>> -Supervisor card 2T
>> -Ios 15.0.SY1
>>
>> I need to do a QoS policing configuration on this hardware, with
>> these
>> conditions:
>>
>> -Mark Dscp value from some types of IP traffic on several layer2
>> INPUT
>> Interfaces of the 6509
>> -Use these DSCPs marks to aply different QoS policings to these
>> flows
>>
>> Is it possible to do all this by configuring only the 6500
>> switch? (this is,
>> without depending of matching the dscp value marked by a
>> diferent device). I
>> read you can not mark the Dscp on the 65000 and also manipulate
>> the same
>> traffic using these Dscps values locally asigned on the 65000.
>>
>> TIA and Best Regards
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>> <http://www.ccie.net/>
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>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> Carlos G Mendioroz <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>> LW7
>> EQI Argentina
>>
>>
>>
>>
>> --
>> Juan Faure
>>
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
>
> Blogs and organic groups at http://www.ccie.net
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Received on Tue May 22 2012 - 10:03:02 ART