Auto QOS changes trust behavior on Interfaces

[maamann]

Hi 

A switch default behavior is , if QOS is not enabled , to trust DSCP marking( or just pass through Marking) . But if I enable auto qos on one interface all the other interfaces are automatically in NON trust state and start rewriting DSCP to 0.

Here my Question; Is there a global command to keep the "trust" or "don't touch marking" state for all the other interfaces where Auto QOS is not explicit enabled ?

To have such a command would be great for migration purposes .

My Switching  Plattform is Cat 4500

regards Markus 

[balaji.bandi]

here is good document : (look at "Generated Auto-QoS Configuration")

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/31sg/configuration/guide/conf/qos.html

[maamann]

Hi Balaji 

thanks for the Link , but that would not answer my question. It only confirms that it is like i described already.

Regards  Markus

[cmarva]

if I understand what you are asking, it would be platform dependent. 

with the classic method of qos, you are correct in that all ports are untrusted unless otherwise configured.

on platforms that support MQC qos, all ports are trusted, and will be remarked according to specific port configs.

so you mention that you have a 4500. unfortunately that alone is not specific enough, because the old sups supported the classic qos model, and the newer sups like the sup7/sup8 support MQC.

[maamann]

hi 

it is a SUP7 and IOS cat4500e-universalk9.SPA.03.06.08.E.152-2.E8.bin.

regards Markus