Limit egress traffic 2960G

Question

This is to support a user who has the requirement of simulating specific speeds for download/upload. We have configured a limit using service-policy that as successfully limiting upload speed (ingress on the interface) but we (more importantly) need to limit download speed (egress on the interface). I know of using srr-queue but we need specific speeds (such as 512KB). Been banging away at this for a few days now and can't find a working method. I pursued shaping via:

class-map match-any CLASS_EgressLimit_512KB
  match access-group name ACL_RateLimit_512KB
policy-map POLICY_EgressLimit_512KB
  class CLASS_EgressLimit_512KB
    shape average 512000
interface gi0/6
  service-policy output POLICY_EgressLimit_512KB

but shaping doesn't seem to be supported in this context on our switch

(WS-C2960G-8TC-L 15.0(2)SE4 C2960-LANBASEK9-M)

Any help is sincerely appreciated!

Answer 1

mls qos aggregate-policer ltusa-5mbps-in 5000000 625000 exceed-action drop
mls qos aggregate-policer ltusa-5mbps-out 5000000 625000 exceed-action drop
mls qos min-reserve 5 170
mls qos min-reserve 6 85
mls qos min-reserve 7 51
mls qos min-reserve 8 34
mls qos
...
class-map match-all cm-ltusa
 match ip dscp default 
!
policy-map pm-ltusa-out
 class cm-ltusa
    police aggregate ltusa-5mbps-out
policy-map pm-ltusa-in
 class cm-ltusa
    police aggregate ltusa-5mbps-in
...
interface FastEthernet0/xxx
 switchport access vlan 4000
 switchport mode access
 fair-queue
 service-policy input pm-ltusa-in
 service-policy output pm-ltusa-out

As far as I recall, that worked on my 3550. (It's not in service anymore.) There's more than one interface in vlan 4000; all have the same configuration. mls qos is the Magic™ to make shaping work on a switch.

Answer 2

The configuration you're trying to use is based on router capabilities, not switch capabilities. While it's true 2960 can do shaping, it's configured in a different way and works in a slightly different way.

Please take a look here to read about the idea, and then when you have configuration get back with any other, specific questions:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_55_se/configuration/guide/scg_2960/swqos.html#wp1200681

One example of configuring sub-rate shaping on interface is proposed here:

http://www.techrepublic.com/blog/data-center/limit-bandwidth-on-a-cisco-catalyst-switch-port/