Rate limit Configuration needed

[kumarpmt83]

Hi,

i have one problem in our office.Iam sitting in the HO location.

In the HO location symantec server is available.This symantec server daily send the update to the client location.

In one of our client location i want to limit the traffic  from the particular symantec server.

our symantec server ip:10.10.150.57

In our client location users(10.50.137.100/24)doesn't receive the traffic beyond 64kb from the source ip(10.10.150.57/22).

They should not be  receive the traffic beyond 64kb.

kindly anyone tell the configuration to implement.

Client location configuration:

int fa0/0(LAN)

ip address 10.50.137.100 255.255.255.0

speed auto

duplex auto

int fa0/1(WAN)

ip address 10.70.125.63 255.255.255.252.0

bandwidth 128

encapuslation PPP

speed auto

duplex auto

[Nataliya Omelyanyuk · Accepted solution]

Hi,

to rate-limit traffic received from server you can do the following:

1) specify access-list describing this type of traffic

access-list 101 permit ip host 10.10.150.57 0.0.3.255 10.50.137.0 0.0.0.255

2) configure rate-limiting on your WAN interface inbound:

rate-limit input access-group 101 64000 12000 24000 conform-action transmit exceed-action drop

Please find below description of this command in more details:

http://www.cisco.com/en/US/partner/docs/ios/12_2/qos/command/reference/qrfcmd8.html#wp1037428

You can also use more flexible way of configuring QoS policies - policing with MQS:

http://www.cisco.com/en/US/partner/docs/ios/12_2/qos/command/reference/qrfcmd5.html#wp1064737

BR,

Nataliya

[kumarpmt83]

Thank u very much.

it is working.

But i have one doubt.what is  12000 24000

how to calculate these values.

what is the use of these values.

[Nataliya Omelyanyuk]

Hi,

Regarding the values you asked for:

first of them is normal burst size, in bytes. The minimum value is bps divided by 2000; Cisco recommended formula for its calculation is as follows:

normal burst = configured rate * (1 byte)/(8 bits) * 1.5 seconds

Second one - excess burst size, in bytes:

extended burst = 2 * normal burst

BR,

Nataliya

[kumarpmt83]

What is normal burst and extended burst?

waht is the use of these.

[Nataliya Omelyanyuk]

Hi,

Traffic flow in network is not constant - sometimes it has bursty nature.

To minimize traffic loss in case of policing, you can define additional rates as follows:

•Normal burst size. The normal burst size determines how large traffic bursts can be before some traffic exceeds the rate limit.

•Excess Burst size. The Excess Burst (Be) size determines how large traffic bursts can be before all traffic exceeds the rate limit. Traffic that falls between the normal burst size and the Excess Burst size exceeds the rate limit with a probability that increases as the burst size increases.

You can read more about average rate, normal and extended burst following the link

http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfpolsh.html#wp1000977

BR,

Nataliya

[kumarpmt83]

Thank u very much.

Can u share any document how BGP works.