[c-nsp] Switch 3750-24p / ratelimit and/or traffic shaping

[Brad Henshaw]

Cedric Gavage wrote:
 
> The goal is to limit the bandwith for one computer connected on one
> interface... For example, to authorize max 5 Mbits for this computer
> (incoming and outgoing traffic)...
 
The best you can hope for is to rate-limit outbound traffic to the PC and police it inbound from the PC. Policing will impact TCP flows pretty badly.
 
Assuming a 100Mbps connection to the PC:
 
policy-map police-5mbps
 class class-default
  police 5000000 bc 8000 exceed-action drop
 
int fa x/y
  srr-queue bandwidth limit 10
  service-policy input police-5mbps
 
Note:
'srr-queue bandwidth limit' specifies a percentage of the port speed which will be used for egress rate limiting. 10 is the minimum value - so in this example, assuming a 100Mbps connection, traffic will be limited to 10Mbps. If you forced the port to 10Mbps you could limit it to 5Mbps by setting the limit to '50'.
 
Alternatively if all traffic to this PC is always entering the switch via a known port you could apply an ingress policy-map with a policer at that point.
 
Check the software configuration guide for the particular IOS version you're running on the 3750 for more info.
 
Regards,
Brad