05-05-2008 08:09 AM - edited 03-05-2019 10:46 PM
Hello
We have a video conf. unit (10.x.x.3) connected to gig9/2 on a 6500 w/ Sup. 720. Connected to gig1/1 is our MPLS router.
If we monitor 9/2 we see the packets being tagged properly with dscp 46 - which is what we expect.
If we monitor gig1/1 we see that packets are now tagged dscp 0 (default). What gives?
Here's the config:
interface GigabitEthernet9/2
description *** Video unit ***
no ip address
logging event link-status
speed 100
duplex full
mls qos trust extend
mls qos trust cos
switchport
switchport access vlan 15
switchport mode access
power inline never
spanning-tree portfast
service-policy input VIDEO
=============================
interface GigabitEthernet1/1
description *** WAN ***
no ip address
logging event link-status
speed 100
duplex full
wrr-queue cos-map 1 2 2
priority-queue cos-map 1 3 5
mls qos trust dscp
switchport
switchport access vlan 6
switchport mode access
power inline never
spanning-tree portfast
===============================
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos
class-map match-any VIDEO
match access-group name VIDEO
policy-map VIDEO
class VIDEO
set dscp ef
ip access-list extended VIDEO
permit ip any host 10.x.x.3
permit ip host 10.x.x.3 any
===============================
I would've expected the QoS marking to be preserved throughout.
Thanks in advance!!
Solved! Go to Solution.
05-05-2008 12:27 PM
Your trust statement is screwing up the final DSCP on the packet. Since you are trusting CoS, and it looks like there is no trunking/802.1P value to use, it is setting the internal DSCP to 0. You don't see this until the packet leaves the switch though, since remarking occurs on egress.
See this section and diagram for more info:
So, remove the mls qos trust statements and just let the policy-map do its work and you should see better results.
05-05-2008 12:27 PM
Your trust statement is screwing up the final DSCP on the packet. Since you are trusting CoS, and it looks like there is no trunking/802.1P value to use, it is setting the internal DSCP to 0. You don't see this until the packet leaves the switch though, since remarking occurs on egress.
See this section and diagram for more info:
So, remove the mls qos trust statements and just let the policy-map do its work and you should see better results.
05-06-2008 03:33 AM
Thank you very much!
09-21-2011 12:24 PM
I just saw this post - How were you monitoring the links to see that packets were getting marked or not? Were you spanning a port and doing a packet capture, or is the a 6500 command that allows you to see the markings?
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