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New Member

QoS isn't working properly in Catalyst 6500

Hi All,

Not sure if anyone also experienced the similar issue as i did. I'm having Cisco Catalyst with GE module (WS-X6748-GE-TX). I'm trying to limit bandwidth for a customer to 4Mbps but the bandwidth always exceed to 5Mbps or more than this. I've verified the QoS configuration, it seems to be correct. Any idea what is the possible issue? Any bug or any IOS/Module of the switch problem? Below are device spec. and configuration.

Appreciate any response.


#show module 1

Mod Ports Card Type                              Model              Serial No.

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

  1   48  CEF720 48 port 10/100/1000mb Ethernet  WS-X6748-GE-TX     SAL13442T95


#show version

Cisco IOS Software, s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M), Version 12.2(33)SXI3, RELEASE SOFTWARE (fc2)

Technical Support:

Copyright (c) 1986-2009 by Cisco Systems, Inc.

Compiled Tue 27-Oct-09 11:12 by prod_rel_team


#show mls qos

  QoS is enabled globally

  Policy marking depends on port_trust

  QoS ip packet dscp rewrite enabled globally

  QoS serial policing mode disabled globally

  Input mode for GRE Tunnel is Pipe mode

  Input mode for MPLS is Pipe mode

  Vlan or Portchannel(Multi-Earl) policies supported: Yes

  Egress policies supported: Yes

  QoS 10g-only mode supported: Yes [Current mode: Off]


#show policy-map 4Mbps

  Policy Map 4Mbps

    Class class-default

     police cir 4000000 bc 128000 be 128000

       conform-action transmit

       exceed-action drop

       violate-action drop

#show run int gi1/5

Building configuration...

Current configuration : 188 bytes


interface GigabitEthernet1/5

ip address X.X.X.X mask X.X.X.X

service-policy input 4Mbps

service-policy output 4Mbps



QoS isn't working properly in Catalyst 6500

Hello Vannara

Please have a look at this



Please don't forget to rate any posts that have been helpful. Thanks.
New Member

QoS isn't working properly in Catalyst 6500

Hi Paul, Thanks for your reply. I've red the above link and a few others related topics, however i'm yet still not able to pinpoint the cause of this issue. I've also red below link and not sure if it is really the cause. I checked the switch interface and found the port was set to "untrusted". If you found out something wrong, kindly share with me.

#show queueing interface gigabitEthernet 1/5

Interface GigabitEthernet1/5 queueing strategy:  Weighted Round-Robin

  Port QoS is enabled

Trust boundary disabled

  Port is untrusted

  Extend trust state: not trusted [COS = 0]

  Default COS is 0

    Queueing Mode In Tx direction: mode-cos

    Transmit queues [type = 1p3q8t]:

New Member

QoS isn't working properly in Catalyst 6500

Hi All,

Any idea on above matter? Hope for any reply from you guys.

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