Solved: MPLS QoS with Uniform tunnel mode

ty.chan007 · ‎01-02-2012

Hi, I am trying to test all mode of MPLS QoS tunnle mode like uniform,etc.

My diagram is as below:

CE01 --access--> ME4900 --trunk--> PE01 --ldp--> P01 --ldp--> P02 --ldp--> PE02 --access--> CE02

All traffic from CE01 are marked with DSCP AF31 an send to PE01. But PE01 can not see packet with AF31.

On ME4900, i just config access port and trunk port only. Nothing else were config on ME4900.

What should be the problem? or Does ME4900 reset DSCP value to 0 by default? if yes, how to fix it?

Vaibhava Varma · ‎01-02-2012

Hi Chanty

Can you try enabling the below command under ME4900 Gi1/7 interface and check

mls qos trust dscp

Regards

Varma

View solution in original post

Vaibhava Varma · ‎01-02-2012

Hi Chan

Are you providing L3 VPN or L2 VPN services between CE01 and CE02..If its L2VPN then in my understanding we would not be able to see the DSCP marking at PE01 trunk interface towards ME4900.

If we send an AF31 packet from CE01 and don't alter anything in the MPLS Backbone and egress PE02 then on CE02 we should receive the same AF31 marking..

Regards

Varma

ty.chan007 · ‎01-02-2012

Hi Varma,

Thanks for reply.

I am doing L3 VPN and PE01 is not able to see AF31 when i sent the packet with AF31 from CE01.

I check on ME4900 and i got below result:

ME4900#sh qos

QoS is disabled globally

IP header DSCP rewrite is enabled

Is that could the problem that PE01 can not see AF31 as ME is rewriting the IP DSCP value?

Regards,

chanty

Vaibhava Varma · ‎01-02-2012

Hi Chan

Can you check the cos-dscp mutation map for the default rewrite happening on the ME4900..On the Uplink trunk interface to PE01 are you trusting cos or dscp ?

On PE01 are you doing a dot1q subinterface config or VLAN SVI based config..Where did you check for the AF31 marking at PE01 on the L2 Trunk Interface or L3-dot1q subbinterface or L3 SVI ?

Note:Edited: And how about checking at CE02 whether the AF31 marking is received or not ?

Regards

Varma

ty.chan007 · ‎01-02-2012

Hi Varma,

1. I am not quite sure how to check cos-dscp mutation map. could you advise the command or doc? note: QoS is disable on ME4900 and there is not QoS config at all on ME4900. Eveything is kept at it default config.

2. I am doing subinterface as gateway for CE01. I am verifying the marking on subinterface with policy-map. I just create class to match with AF31 and apply to the interface.

Vaibhava Varma · ‎01-02-2012

Hi Chan

Please check for below commands on ME4900

show mls qos

show mls qos maps

Also please share the uplink trunk interface config for ME4900 to PE01

Regards

Varma

ty.chan007 · ‎01-02-2012

Hi Varma,

Below are the result:

interface GigabitEthernet1/7

description CONNECT-TO-PE-01

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 76,88,89,94,101,1346,1370,1414,1503

switchport mode trunk

end

ME4900#sh mls qos

QoS is disabled globally

IP header DSCP rewrite is enabled

ME4900#sh mls qos maps

DSCP-TxQueue Mapping Table (dscp = d1d2)

d1 : d2 0 1 2 3 4 5 6 7 8 9

-------------------------------------

0 : 01 01 01 01 01 01 01 01 01 01

1 : 01 01 01 01 01 01 02 02 02 02

2 : 02 02 02 02 02 02 02 02 02 02

3 : 02 02 03 03 03 03 03 03 03 03

4 : 03 03 03 03 03 03 03 03 04 04

5 : 04 04 04 04 04 04 04 04 04 04

6 : 04 04 04 04

Policed DSCP Mapping Table (dscp = d1d2)

d1 : d2 0 1 2 3 4 5 6 7 8 9

-------------------------------------

0 : 00 01 02 03 04 05 06 07 08 09

1 : 10 11 12 13 14 15 16 17 18 19

2 : 20 21 22 23 24 25 26 27 28 29

3 : 30 31 32 33 34 35 36 37 38 39

4 : 40 41 42 43 44 45 46 47 48 49

5 : 50 51 52 53 54 55 56 57 58 59

6 : 60 61 62 63

DSCP-CoS Mapping Table (dscp = d1d2)

d1 : d2 0 1 2 3 4 5 6 7 8 9

-------------------------------------

0 : 00 00 00 00 00 00 00 00 01 01

1 : 01 01 01 01 01 01 02 02 02 02

2 : 02 02 02 02 03 03 03 03 03 03

3 : 03 03 04 04 04 04 04 04 04 04

4 : 05 05 05 05 05 05 05 05 06 06

5 : 06 06 06 06 06 06 07 07 07 07

6 : 07 07 07 07

CoS-DSCP Mapping Table

CoS: 0 1 2 3 4 5 6 7

--------------------------------

DSCP: 0 8 16 24 32 40 48 56

Regards,

chanty

Vaibhava Varma · ‎01-02-2012

Hi Chanty (sorry I was using wrong name till now..)

Since the MLS QoS is disabled globally everyhting should be passed unalteredly. Can you check and share for the trust state of the uplink interface Gi1/7 on ME4900 using

show mls qos interface Gi1/7

Regards

Varma

ty.chan007 · ‎01-02-2012

ME4900#sh mls qos int g1/7

QoS is disabled globally

Port QoS is enabled

Administrative Port Trust State: 'untrusted'

Operational Port Trust State: 'dscp'

Trust device: none

Default DSCP: 0 Default CoS: 0

Appliance trust: none

Tx-Queue Bandwidth ShapeRate Priority QueueSize

(bps) (bps) (packets)

1 250000000 disabled N/A 2080

2 250000000 disabled N/A 2080

3 250000000 disabled normal 2080

4 250000000 disabled N/A 2080

ME4900#

Vaibhava Varma · ‎01-02-2012

Hi Chanty

Can you try enabling the below command under ME4900 Gi1/7 interface and check

mls qos trust dscp

Regards

Varma

ty.chan007 · ‎01-02-2012

Hi Varma,

Any performance impact when turn it on? How about access port, do i need to turn it on too?

Regards,

chanty

Vaibhava Varma · ‎01-02-2012

Hi Chanty

If on the access port we are not doing any trust device or trust cisco-phone which is typical of an enterprise scenario then we would need to trust dscp on Access Link ( we can't use cos as its Access Port and no VLAN Info)

Please see below link for same which gives a nice explaination.

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_tech_note09186a0080883f9e.shtml

Regarding the impact of introducing this command in a production network, I can say from my personal experience and understanding this should not create any issue untill unless there is congestion as QoS is needed for avoiding congestion.Hope I make myself clear on this point..

Regards

Varma

ty.chan007 · ‎01-02-2012

Hi Varma,

Wow, many thanks for great advise and kindly help.

I will get back to you after i get the result.

Regards,

chanty

ty.chan007 · ‎01-02-2012

Hi Varma,

Another strang output:

ME4900#sh mls ?

% Unrecognized command

ME4900#sh mls qos ?

% Unrecognized command

ME4900#sh mls qos

QoS is disabled globally

IP header DSCP rewrite is enabled

It looks like mls command is not available but it work when i just enter it??

Regards,

chanty

Vaibhava Varma · ‎01-02-2012

Hi Chanty

Can you check for the IOS Code of the ME4900 in the Cisco-Feature Navigator and see for MLS feature there..

I have see this a couple of times before same behaviour due to IOS..

Regards

Varma