cisco 3550 Qos DSCP marking

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06-08-2010 01:12 AM - edited 03-06-2019 11:28 AM
I have the following setup :
device marking dscp >------>trunk port [3550 switch] ----- access port---------> management computer
The device is marking with dscp 6 in upstream. I need to be able to recognise the dscp 6 marking on the switch and also performing the dscp marking 6 on downstream on the switch for allowing traffic to pass.
Also, I need the management computer to be able to access the device marking dscp, meaning that I need to replace the dscp marking with no marking.
I have the following config :
interface FastEthernet0/1
description TRUNK_4MOTION_ODU
switchport trunk encapsulation dot1q
switchport mode dynamic desirable
service-policy input ACS
mls qos trust dscp
interface FastEthernet0/5
description MANAGEMENT_CPE
switchport access vlan 1101
switchport mode access
service-policy input ACS
spanning-tree portfast
access-list 120 permit ip 10.101.0.0 0.0.0.255 any dscp 6
ip dhcp pool MANAGEMENT_CPE
network 10.101.0.0 255.255.255.0
domain-name test.com
default-router 10.101.0.254
option 60 ascii "dslforum.org"
option 43 ascii "InternetGatewayDevice.ManagementServer.URL=http://10.101.0.252:8080/dps/TR069"
lease 0 0 5
class-map match-all ACS
match access-group 120
policy-map ACS
class ACS
set dscp 6
!
For some reasons I cannot pass any traffic between the device marking with dscp 6 and my switch.
What am i missing ?
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06-08-2010 03:18 AM
Liviu,
Fa0/1 is a trunk
Fa0/5 is a switchport in vlan 1101
By default all packets recevied on the trunk ports WITHOUT a dot1q marking in the layer 2 header will be assumed to be on VLAN 1. Since the trunkport is in VLAN 1 and your management station is in VLAN 1101 - you need inter VLAN routing.
HTH>
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06-08-2010 04:37 AM
Hi Andrew,
Thanks for your prompt response.
I think I already "instruct" the trunk port to accept qos-marked packets.
I am not quite sure if I got your point. Inter-vlan routing is being done at the moment on the 3550 switch.
My concern is not on that side, but I assume i am doing something wrong on the policer side.
Liviu

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06-08-2010 04:47 AM
What IP address is the Managent Device?
What IP address is the Device marking the traffic?
What VLAN is the device marking the traffic in?
Can you ping between the devices?
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06-08-2010 05:04 AM
The device marking the traffic should get an IP from this pool :
ip dhcp pool MANAGEMENT_CPE
network 10.101.0.0 255.255.255.0
domain-name test.com
default-router 10.101.0.254
option 60 ascii "dslforum.org"
option 43 ascii "InternetGatewayDevice.ManagementServer.URL=http://10.101.0.252:8080/dps/TR069"
lease 0 0 5
.
And it gets it.
The management computer's IP address is on 10.101.0.252 and it is on VLAN 1101.
Behind the CPE I am using multiple VLANs, that's why I am using trunking.
On the switch side, I want to be able to recognise dscp 6 marked on the CPE, assign an IP from DHCP pool residing on VLAN 1101 and be able to pass traffic.
At the moment I cannot ping the device performing marking.

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06-08-2010 05:11 AM
Check your routing
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06-08-2010 05:58 AM
My question actually is that if you can associate service policies to trunk ports..

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06-09-2010 12:37 AM
Yes you can.
HTH>
