What is the best way to trust DSCP values on 6509 interfaces?

[jkeeffe]

I have 6509's with 2 Ten-gig interfaces configured into a Port Channel (routed with IP addressing) - the IOS is 12.2(18)SXE3. I want to trust the DSCP values of packets traveling through the interfaces and have applied 'mls qos trust dscp' on both the physical Ten-gig interfaces as well as the L3 Port Channel interface.

1.Is it necessary to have the statement on all the interfaces, or is just having it on the Port channel enough?

Here is the config right now:

interface Port-channel4

description to 6509-Core-A P4 (T1/3, T2/3)

ip address 164.xxx.xx.xx 255.255.255.252

ip pim sparse-mode

ip route-cache flow

mls qos trust dscp

!

interface TenGigabitEthernet1/1

description to 6509-Core-A T1/3 (P4)

no ip address

ip route-cache flow

mls qos trust dscp

channel-group 4 mode desirable

!

interface TenGigabitEthernet1/2

description to 6509-Core-A T2/3 (P4)

no ip address

ip route-cache flow

mls qos trust dscp

channel-group 4 mode desirable

Also, what command can I use to see the dscp counters? In the 3560/3750 catalyst line you can enter: 'sh mls qos int f0/1 statistics' and get a display of all the dscp/cos input/output packet counts, but I can't find a comparable command in the 6509.

2. Is there one?

[gwhuang5398]

I think you do this on the individual port interfaces, not the port-channel interface, becasue the queueing mechanisims associated with DSCP values are port based.

By doing this, if you have policy maps you want to use, you attach them to the ports not the port-channel.

For the command on 6509, you can use:

sh mls qos ip gigabitEthernet 1/1

Hope this helps and let me know how that works out.

Gary