[Hidden-tech] Cisco Router rate limiting

[David Korpiewski]

The rate limit is working according to what I see, thank you for that 
command:

springfield-wan#show interface FastEthernet0/0 rate-limit
FastEthernet0/0
   Input
     matches: access-group 101
       params:  24000 bps, 10000 limit, 10000 extended limit
       conformed 312738 packets, 48202703 bytes; action: transmit
       exceeded 18718 packets, 17052949 bytes; action: drop
       last packet: 408ms ago, current burst: 3648 bytes
       last cleared 1d13h ago, conformed 2000 bps, exceeded 1000 bps
   Output
     matches: access-group 101
       params:  24000 bps, 10000 limit, 10000 extended limit
       conformed 41 packets, 21050 bytes; action: transmit
       exceeded 0 packets, 0 bytes; action: drop
       last packet: 1142276ms ago, current burst: 0 bytes
       last cleared 1d13h ago, conformed 0 bps, exceeded 0 bps
springfield-wan#


I'd be interested in knowing how to do resource reservation for 
preferred traffic instead.  Any advice would be very appreciated :-)

Thank you
David


On 10/25/2010 9:49 PM, R. David Murray wrote:
> 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

-- 
===========================================
David Korpiewski
Software Specialist I
CSCF - Computer Science Computing Facility
Department of Computer Science
Phone: 413-545-4319
Fax:   413-577-2285
===========================================