Rate limit a subnet with shaping as opposed to policy

[atmpinniatm]

My research has lead me to 2 areas for  configuration of shaping. Apply shaping on class-map and/or the policy-map??

Objective = limit subnet to 256K at all times.

Access-list 1 permit <subnet>

Class-map 256k_limit

Match access-group 1

bandwidth  256000 (not sure if this is required/relevant) 

shape  peak 256000

policy-map  256K_choke

class  256k_limit

(perhaps shaping should be applied here??)

int  xyz

service-policy output 256K_choke (FYI data to be choked comes in on interface  abc and out on xyz)

I understand from my previous discussion/port that shaping will provide users on subnet xyz with better performance as buffering would be used should bandwidth increase above 256K.

This is my previous solution with policy

access-list 1 permit <subnet>

class-map 256_limit

match access-group 1

exit

policy-map subn_rate_limit

class 256_limit

police 256000 conform-action transmit  exceed-action drop  violate-action drop

interface g0/0

service-policy output subn_rate_limit

Am on on the right track?

[Giuseppe Larosa · Accepted solution]

Hello John,

you are on the right track

Class based shaping can be applied outbound and the change is in the policy-map configuration where the action is changed from police .... to shape.

see command reference for shape command in policy map context

http://www.cisco.com/en/US/docs/ios/qos/command/reference/qos_s1.html#wp1068912

Hope to help

Giuseppe