[nsp] Bandwidth Cap Question

Alexandre Snarskii snar at paranoia.ru
Fri Mar 28 13:52:30 EST 2003


On Fri, Mar 28, 2003 at 08:16:38AM +0100, sthaug at nethelp.no wrote:
> > 	I have a 6500 running in native mode, and I'm
> > wondering whats the best way to cap VLANs or specific
> > subnets. I've tried setting up Qos Policers for 1Mbps
> > but it did not work well at all, and was only able to
> > do a few kB/s. TAC told me its because of TCP and
> > theres no way around it.
> 
> If you're trying to limit bandwidth on *output*, the current 6500
> hardware (Sup2/PFC2) simply cannot do it. Has nothing do to with 
> TCP and everything to do with the hardware implementation.

Hmmm... Just tried CAR my computer with 6500/native (msfc2/pfc2): 

Interface configuration with policy applied: 
interface Vlan155
[...]
 rate-limit output access-group 199 256000 48000 96000 conform-action transmit exceed-action drop

access-list 199 permit ip any host x.x.x.x
access-list 199 deny   ip any any

Getting ftp receive rate: 
2243759 bytes received in 79.47 secs (27.6 kB/s)

FTP'ing the same file from the same host within seconds after 
(just those seconds required to drop rate-limit statement from configuration):

2243759 bytes received in 7.73 secs (2.8e+02 Kbytes/sec)

IOS version is: 

IOS (tm) c6sup2_rp Software (c6sup2_rp-JSV-M), Version 12.1(11b)E4, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)



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