QoS in Catalyst 2950 switch

[antoniolv]

Do you know if it is possible to apply QoS in a Catalyst 2950 switch?. I have tried to configure it in an interface and it only allows me "service-policy input" and I need to apply it as " service-policy out."

Thanks,

[Georg Pauwen]

Hello,

this is from a previous post:

You can only police ingress traffic on a CAT2950.

Cat2950(config-if)#service-policy ?

input Assign policy-map to the input of an interface

You can workaround by policing at ingress on the uplink as well((which is equivalent to policing egress on all interfaces).

HTH,

GP

[antoniolv]

Hi,

this solution is not suitable for our case because we have to limit the outbound flow on the uplink interface.

Thanks

[Kevin Dorrell]

Antonio,

You cannot police or shape the outgoing traffic on a 2950, but there are indirect ways to achieve what you want. It depends on why you want to limit the outbound raffic. If your issue is simply that you want to limit the traffic coming from this switch into the distribution layer, then you could simply police the traffic on ingress to the distribution switch. But I guess you were after a more sophisticated solution.

What you can do is to use service-policy in the ingress interfaces of the 2950 to classify the traffic and set the CoS on the packets. (You can also set DSCP if that is useful later on in your network.) You can then use WRR to profile the bandwidth outbound on the uplink port. This only works if you have a trunk to the distribution layer BTW. Then if you police the traffic on the ingress to the distribution layer, it will be the less important traffic that is more likely to be dropped.

Hope this helps.

Kevin Dorrell

Luxembourg