RATE-LIMIT

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Dec 22nd, 2008
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I am confusing about use the rate-limit. I have a router 2800 and this router has some Fast Ethernet sub-interfaces to differents segments.


This example of configuration, should to guarantee that a link 256 will not use more than 256?


I need to limit the use of link in each of segments to be sure that each segment will not consume more than what need it.


rate-limit input 256000 256000 256000 conform-action transmit exceed-action drop

rate-limit output 256000 256000 256000 conform-action transmit exceed-action drop

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tomek0001 Mon, 12/22/2008 - 19:14
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I found this on cisco's website, should be helpful:


"Usage Guidelines


Use this command to configure your CAR policy on an interface. To specify multiple policies, enter this command once for each policy.


CAR and DCAR can be configured on an interface or subinterface.


Policing Traffic with CAR


CAR embodies a rate-limiting feature for policing traffic. When policing traffic with CAR, Cisco recommends the following values for the normal and extended burst parameters:


normal burst (in bytes) = configured rate (in bits per second) * (1 byte)/(8 bits) * 1.5 seconds


17.000.000 * (1 byte)/(8 bits) * 1.5 seconds = 3.187.500 bytes


extended burst = 2 * normal burst


2 * 3.187.500 = 6.375.000 bytes


With the listed choices for parameters, extensive test results have shown CAR to achieve the configured rate. If the burst values are too low, then the achieved rate is often much lower than the configured rate.


For more information about using CAR to police traffic, see the "Policing with CAR" section of the "Policing and Shaping Overview" in the Cisco IOS Quality of Service Solutions Configuration Guide. "

guruprasadr Mon, 12/22/2008 - 20:40
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HI, [Pls RATE if HELPS]


CAR values for 256K Link:

rate-limit input access-group 150 2560000 480000 960000 conform-action transmit exceed-action drop

rate-limit output access-group 150 2560000 480000 960000 conform-action transmit exceed-action drop


Another format of applying the CAR is using the Cisco - Police:


To apply CAR for a customer whose bandwidth is 256, please follow as below,

!

policy-map Customer-VSI-IN

class class-default

police 256000 conform-action transmit exceed-action drop

!

policy-map Customer-VSI-OUT

class class-default

police 256000 conform-action transmit exceed-action drop


Apply the policy-map in the interface as below:

!

service-policy input Customer-VSI-IN

service-policy output Customer-VSI-OUT



Hope I am Informative.


PLS RATE if HELPS


Best Regards,


Guru Prasad R

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