Hey Gian, I'm pretty sure you need both commands in order for this to work. If you test this with the AutoQoS macro you will see that both commands are configured on the port:
Cat3560-2(config)#int g0/30 Cat3560-2(config-if)#auto qos voip cisco-phone Cat3560-2(config-if)#do sh run int g0/30 | i mls mls qos trust device cisco-phone <-- instructs the switch to trust the phone mls qos trust cos <-- instructs the switch to use CoS as the trust mode Let's default the configuration and look at what we see: Cat3560-2(config-if)#default int gig0/30 Interface GigabitEthernet0/30 set to default configuration Here is what the port looks like in its default state, here we are obviously not trusted with no trust device Cat3560-2(config-if)#do sh mls qos int gig0/30 GigabitEthernet0/30 trust state: not trusted trust mode: not trusted trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: none qos mode: port-based If we ONLY configure mls qos truse cos the trust mode is cos but the trust device is none Cat3560-2(config)#int gig0/30 Cat3560-2(config-if)#mls qos trust cos Cat3560-2(config-if)#do sh mls qos int gig0/30 GigabitEthernet0/30 trust state: trust cos trust mode: trust cos trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: none qos mode: port-based If we add the other command we see that we are good Cat3560-2(config-if)#mls qos trust device cisco-phone Cat3560-2(config-if)#do sh mls qos int gig0/30 GigabitEthernet0/30 trust state: trust cos trust mode: trust cos trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: cisco-phone qos mode: port-based Cheers! Thank you. Steve Di Bias Network Engineer - Information Systems Valley Health System - Las Vegas Office - 702- 369-7594 Cell - 702-241-1801 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Gian Paolo Sent: Tuesday, April 12, 2011 10:41 AM To: IPX ccie_rs Subject: [OSL | CCIE_RS] mls qos trust cos Hi experts, I'm reviewing L2 QoS on 3560 and I need a clarification. If a cisco phone must be trusted on a port, do I need to add "mls qos trust cos" or just "mls qos trust device cisco-phone" is enough? On IPX VoD slide 718 or minute 96:32 of QoS lecture there are both, on Doc-CD example only one but it says "depending on trust setting": http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_58_se/command/reference/cli1.html#wp11906329 Regards, Gian Paolo _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com UHS Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient (s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this information is prohibited. If this was sent to you in error, please notify the sender by reply e-mail and destroy all copies of the original message. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
