11-10-2011 09:13 AM - edited 03-07-2019 03:19 AM
Hello,
I have some trouble with that policy-map on my 2960 or 3560 switches with LAN base 12.2(53)SE2.
I want to use that feature to catch video traffic from webcams in laptops which can't send dscp values out of the box.
This is my test config to check if the function is working:
!
! catch every traffic from my workstation for testing
!
access-list 101 permit ip any any
!
class-map match-all CL_TEST
match access-group 101
!
!
! set dscp to 41 for all traffic
!
policy-map PM_TEST
class CISCO
set ip dscp af41
!
interface fastethernet 0/1
service-policy input PM_TEST
!
I see two problems:
1. I can't see any counters with the command "sh policy-map interface FastEthernet 0/1". Cisco tells that this command is not possible.
But how I can see if the policy is woring correct?
2. When I did the configuration I can't see any pakets with dscp af41 on the out going interface on the switch with "sh mls qos int gi0/1 statistic" as I expected. After reloading the switch I see the pakets with af41. Okay for that moment.
But.....
After that I changed something in the policy-map. Only "set ip dscp ef" for a second test.
Generating some traffic I see only pakets with af41 as before I changed the policy-map. No traffic with ef on the outgoing interface.
My asumption is that I can configure that feature, but the switch is not able to write the config down to its TCAM or something like that.
Only with a reboot the policy-map will be written correct down to the hardware and will work as it should.
Do anybody know something about that?
Thanks a lot for every advice.
Sven
11-12-2011 08:44 AM
I did some more research on this issue and think now that the problem is an IOS bug in some versions.
I tried the version 12.2(55)SE1 and it works. I can change the policy-map and it takes effect in the same moment on the input interface.
After that I did tests with the following versions:
12.2(50)SE3 - hits the issue
12.2(52)SE - hits the issue
12.2(55)SE1 - works fine
12.2(58)SE2 - works fine
15.0(1)SE - works fine
So I tink there was a fix between 52 and 55 but I can't find a bug ID for that.
As a workaround to get the changed policy-map working on the input interfaces it helps to delete the "service-policy input
I will inform my case owner in TAC about that and will post the bug ID if there is one.
Sven
11-25-2011 11:55 PM
Thanks for your post. I'd just like to add this line concerning "show policy-map" that I found in the command reference after running into the same issue:
Note
Though visible in the command-line help string, the
control-plane
and
interface
keywords are not supported, and the statistics shown in the display should be ignored.
11-26-2011 03:22 PM
Hello sven
The sh policy map command is not supported for this platform due to hardware limitaion. Following is the documented bug.
"show policy-map interface" in 2960, 2970, 3560, 3750 should give error
Release notes
http://wwwin-tools.cisco.com/dir/details/johgill
Symptom:
"show policy-map interface" shows no matches
Conditions:
This command is run on one of the following switches:
2950
2960
2970
3550
3560
3750
Workaround:
This is a hardware limitation and these switches do not support this output. There is no workaround.
---------------------------------------------------------------------------------------------
But you can use the following commnad to see statistics and its really helpful and if the policer dropping traffic, it will show under out of profiler.
-2960-2#sh mls qos interface gigabitEthernet 1/0/1 statistics
GigabitEthernet1/0/1 (All statistics are in packets)
dscp: incoming
-------------------------------
0 - 4 : 0 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
dscp: outgoing
-------------------------------
0 - 4 : 0 0 0 0 0
5 - 9 : 0 0 0 0 0
10 - 14 : 0 0 0 0 0
15 - 19 : 0 0 0 0 0
20 - 24 : 0 0 0 0 0
25 - 29 : 0 0 0 0 0
30 - 34 : 0 0 0 0 0
35 - 39 : 0 0 0 0 0
40 - 44 : 0 0 0 0 0
45 - 49 : 0 0 0 0 0
50 - 54 : 0 0 0 0 0
55 - 59 : 0 0 0 0 0
60 - 64 : 0 0 0 0
cos: incoming
-------------------------------
0 - 4 : 0 0 0 0 0
5 - 7 : 0 0 0
cos: outgoing
-------------------------------
0 - 4 : 0 0 0 0 0
5 - 7 : 0 0 0
output queues enqueued:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 0
queue 3: 0 0 0
output queues dropped:
queue: threshold1 threshold2 threshold3
-----------------------------------------------
queue 0: 0 0 0
queue 1: 0 0 0
queue 2: 0 0 0
queue 3: 0 0 0
Policer: Inprofile: 0 OutofProfile: 0
02-20-2012 10:09 PM
Hey,
I want to update this thread because I got feedback from cisco.
It is not recommended by cisco to use a policy-map together with the command "mls qos trust cos" on the same interface. It is working on some IOS, but not on all. That is not a bug!
To get both features running we had to build the function of "mls qos trust cos" inside the policy-map and then use only this for trusting or marking the dscp or cos values.
After deleting the "mls qos trust cos" the policy-map is working directly after I change a value inside.
Thanks for the help!
Sven
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