Cisco 3560G - QoS traffic-policing question

[rainman]

Hello,

I'm trying to configure a copper-based GigabitEthernet port on a Cisco 3560G to support a speed of 6Mb/s input/output.

I can create a QoS policy-map to limit the port to 6Mb ingress, however when I try to apply the policy to the port as Egress, the switch tells me it is not supported:

C3560G (config-if)#service-policy output 6MB-EGRESS
Warning: Assigning a policy map to the output side of an interface not supported

Service Policy attachment failed
Warning: Assigning a policy map to the output side of an interface not supported


There is another QoS method I can use to police egress traffic (srr-queue bandwidth limit X), however the range is 10-90, and in my case I would want to do 6% of 100Mbit to ensure the port gets 6Mb/s.

Is there a proper way to do traffic policing on egress ports? I dont want this port to get 10Mb/s.


-Rainman

 

[ADB100]

You can't do this on the 3560 or 3750 (as well as 2970, 2960) since they don't support egress policing. It's a bit of a shame really since the previous 3550 switches do support this feature.
The 'srr-queue bandwidth limit' command as you state is limited to a minimum of 10% of the link speed - i.e. 10Mbps on a 100Mbps interface. Is it possible for you to force the speed of the interface to 10Mbps and then set the 'srr-queue bandwidth limit' to 60 i.e. 6Mbps?

HTH

Andy

 

[rainman]

Yes that works but sometimes I see issues with devices doing 10Mb/s full duplex (at least on 76xx platform). I did manage to talk to Cisco TAC about this and they did confirm those switches do not interface egress queueing however they suggested that instead of trying to police it on the egress port, you can build a policy / ACL to police it on the INGRESS port of the switch itself. This will in turn cause the switch to police the data flow before it hits the egress port so it would do what I want, but my problem is when I have 10 customers that get ethernet handoffs... that's going to be quite a policy map / ACL if it's even possible.

The srr-queue feature does work on 100Mb ports, and it's also supposed to work at 10Mb/s, I've just had bad luck recently with 10Mb full duplex ports... maybe it's not a problem on the 3560 and 3750's but i've had tons of problems on the 7613/6509.


-Rainman