Enabling MLS QoS ON 6500 Running IOS 12.2(18)SXD1

peter_thompson · ‎10-19-2005

I have multiple port channels l2 and l3 running over multiple blades . The blades have different queueing strategies out of the box ..

When you enable mls qos the port channels throw a fit . Dropping all ip comms. Is there any way of getting around this or am I going to have to break the port-channels ?

Note all port channels work beautifuly before enabling qos globally .

I have found documents on cco saying mls qos trust dscp need to be enable on the ports but this does not seem to work.

here is a list of the modules :

WS-X6148V-GE-TX

WS-SUP720-3B

WS-X6148V-GE-TX

WS-X6548-GE-TX

WS-X6748-SFP

can any one help ??

szahid · ‎10-19-2005

two imp points.

1. When QoS is enabled, enter the "no mls qos channel-consistency" port-channel interface command to support EtherChannels that have ports with and without strict-priority queues.

2. Whenever you enable qos , always make sure to do classification. W/o classification , qos can hurt more then it can help. With qos enabled , the ports go into untrusted mode and all traffic ends up mapping to one queue instead of utilizing several queues for different classes. So make sure you do classification ( classification can be done by enabling trust states or through qos acls / policy maps ).

thanks

Salman Z.

peter_thompson · ‎10-21-2005

thank you