[Hidden-tech] Cisco Router rate limiting

[R. David Murray]

On Mon, 25 Oct 2010 16:35:32 -0400, David Korpiewski <davidk at cs.umass.edu> wrote:
> I'm trying to rate limit the traffic on a particular segment to about 
> 30k of the T1 line (128kb) for any Http/Https/ftp traffic.

Not sure how these numbers relate...

> I put in the rate limit commands for input and output, but when I 
> actually perform a test, it still uses up the entire bandwidth on the 
> wire when downloading a file from microsoft.com, for example.

What does 'show interface XXX rate-limit show?

> What is missing that is preventing this from dropping things and keeping 
> the connection down to 30kb/sec?

Is CEF enabled on those interfaces? (Wether or not it will be enabled
by default varies by router and/or IOS version.)  CEF is required
for rate-limit, and I don't remember if you get an error message if
you try to set a limit without CEF enabled.

> The reason that this is necessary is that the web traffic is using up 
> all of the bandwidth and the terminal server clients are having horrific 
> delay.

In that case my normal approach would be to do resource reservation for
the preferred traffic.  That way the other traffic can use the bandwidth
with the preferred traffic isn't active.  Email me if you'd like some
advice on how to set that up.

>   rate-limit input access-group 101 24000 10000 10000 conform-action 

With these numbers you are setting the CAR to only 24K bits per second,
with a burst of 80K bits per second.

--
R. David Murray                                      www.bitdance.com
Business Process Automation - Network/Server Management - Routers/Firewalls