QOS on a 3550-SMI

[bmannella]

Hello,

I need to be able to apply a policer to a single interface on a 3550-SMI limiting all IP inbound and outbound traffic to 1 Meg for a colocation customer.

I have tried to configure this several times and i have read every cisco doc on qos. I am still unable to get it working.

Can someone please help by providing a example config.

Thanks

[smcquerry]

First you have to enable QOS globally on the switch.

3550(config)#mls qos

Next create an Access-list to identify the traffic (easy in this case :-))

3550(config)#access-list 101 permit ip any any

Next create a class map to match the traffic.

3550(config)#class-map iptraffic

3550(config-cmap)#match access-group 101

Next create a policy map for the class map.

3550(config)#policy-map ratemap1meg

3550(config-pmap)#class iptraffic

3550(config-pmap-c)#police 1000000 8192 exceed-action drop

Finally map the policy to the interface.

3550(config)#interface fa 0/1

3550(config-if)#service-policy input ratemap1meg

Save your configs.

[bmannella]

This seems to work great, but one thing. Will the do both input and output. I noticed you only have input mapped to the interface.

Thanks

[marcio.pilotto]

Just a note, only input policer is possible.

[bmannella]

Is there another way to do both input and output. Or is there a reason why i can't do both.

[smcquerry]

The hardware on the 3550 only allows input policers. If you want to limit the amount of traffic going to a particular device, you could put an input policer on the uplink port with the IP address in the access list specific to the destination of the device.