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Rate limiting/Traffic shaping C3750


Hey all,

Need some help on the best way to configure rate limiting and/or traffic shaping for a single interface.

Have a C3750-12S with an interface connected to a 10Mb circuit (leased line)  10Mb is shared over a 2 business units who respectively want 5Mb and 5Mb.

This is a L3 handoff with no trunk/vlan frames going over the circuit.

I want to be able to rate limit on policy I think by class map.


2 x destination networks (targets)          Business  unit 1        Business unit 2

transit is a /29


I think I need to create a class map which will allow me to specify criteria for L3 -L4. Is this correct?

Does mls qos need to be enabled globally? ( i believe so) 

The switch is a production switch how will enabling mls impact the switch?

Would appreciate some example configs if possible.

thanks in advance..



Joseph W. Doherty
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You might try SRR sharing.  Direct you two subnets into two different egress queues and allocate each 50% of the bandwidth.


You could also SRR shaping, but I recommend sharing at it would allow each network to utilize bandwidth unused by the other network.

Hi Amar,

If you are looking to rate limint on some L3 interfaces then you can use class map or rate limit commands directly under the L3 interface.

If you have a seperate Vlan's for example Network-A and Network-B then it would be possible to allocate bandwidth under the vlan's

See the below two individual steps may help in your scenario.


Apply rate-limit on each L3 vlan interface in your 2851

Router# conf t
Router(config)# int vlan 2
Router(config-if)#rate-limit input 1000000 187500 375000 conform-action transmit exceed-action drop
Router(config-if)#rate-limit output 1000000 187500 375000 conform-action transmit exceed-action drop


Policy a specific VLAN number on VLAN interface.

class-map vlan5
match vlan 5
match class-map class-default

policy-map vlan5-limit
class vlan5
police 2000000 250000 exceed-action drop

int vlan5
service-policy input vlan5-limit

After you apply this configuration, the traffic with VLAN 5 coming from any will be policed at 2Mbps.

Hope this will help you.

Please rate the helpfull posts.

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