Marking traffic for QoS before NAT

Unanswered Question
Jul 14th, 2008

I have a Cisco 1801 router connected to the Internet configured wit NAT. An outbound service-policy is configured on the public interface to prioritise an application which is working.

I want to prioritise traffic from one of my wireless clients also so I have configured an extra policy on the interface that the wireless access point is connected to (The wireless AP is not running NAT)

interface FastEthernet7

service-policy input PRENATMAP

class-map match-any PRENAT

match access-group name PRENATACL

policy-map PRENATMAP

class PRENAT

set qos-group 1

ip access-list extended PRENATACL

permit ip host any

I can see traffic being sent by this device but the policy map is showing no matches. I am using the "qos-group" so that I can priortise this traffic after it has been NAT'ed on the public interface and therefore I don't know the source IP anymore.

sh policy-map int f7


Service-policy input: PRENATMAP

Class-map: PRENAT (match-any)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: access-group name PRENATACL

0 packets, 0 bytes

5 minute rate 0 bps

QoS Set

qos-group 1

Packets marked 0

Class-map: class-default (match-any)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: any

I have this problem too.
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tdrais Tue, 07/29/2008 - 06:16

I guess one thing to point out is that the default class also has no matches.

This may be a indication that this is not supported on the switch ports of this router. There are many restriction depending on the switch platform related to QoS.

Try applying the service policy to the layer 3 virtual interface and see if you see any traffic.

stretchlad Tue, 07/29/2008 - 09:08

Thanks for the reply

I tied that also but get the following:

Router(config)#int vlan 1

Router(config-if)#service-policy input PRENATMAP

Configuration failed!

This is an 1801 running 12.4(11)T4 AdvIP Services


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