Hi Steve, thank you for the very clear explanation. I agree both commands are needed, so the port trusts CoS but only if frames are coming from a Cisco Phone device detected via CDP. Sometimes Doc-CD is a bit confusing.
Gian Paolo On 14/apr/2011, at 08.55, Di Bias, Steve wrote: > 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
