RE: Rate-limit on 3750 & BGP

Dear Manoj,

Rate limit command is not supported for hardware switched traffic on
Cisco switches. You might consider using MQC QOS features to achieve the
same. You could police the inbound traffic on a 3750 switch but not the
outbound traffic. To rate limit the outbound traffic you might consider
a workaround where you would map the FTP traffic to a separate hardware
queue and then shape that hardware queue at appropriate bandwidth.

Here is a sample config that might help for inbound policing:

access-list 100 permit tcp any any eq ftp
!
Class-map FTP
 Match access-group 100
!
Policy-map FTP
 Class FTP
  police 512000000 102400 exceed-action drop
!
Interface g0/1
 Service-policy input FTP
!

Regarding the number of BGP routes on 3750, the limitation is on the
number of routes that can be forwarded in hardware. There is limited
TCAM space in the 3750, with the "aggregator default" SDM template you
are limited to 12k unicast routes. This is further broken down into
directly connected hosts and indirect routes
with an allocation of 6k for each. Once TCAM resources are exhausted the
switch will have to perform forwarding in software and this can have
amajor performance impact including packet loss and loss of routing
protocol adjacencies.

Thanks and regards,

Ruchir

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
manoj prajapati
Sent: Wednesday, November 18, 2009 11:57 AM
To: Cisco certification; cisco_at_groupstudy.com
Subject: Rate-limit on 3750 & BGP

Hi,

   I have enable Rate-limit on CISCO 3750 switch to limit the bandwidth
512k for FTP traffic
Below is the configuration.

int g1/0
rate-limit input access-group 100 512000 1024000 2048000 conform-action
transmit exceed-action drop
rate-limit output access-group 100 512000 1024000 2048000 conform-action
transmit exceed-action drop

access-list 100 permit tcp any any eq ftp

After enabling the rate-limit on the switch. I am not able to get any
difference with rate-limit (there is no hitcount on the ACL). Is there
anything i am missing ??

1 more question how many BGP routes can 3750 supports ?

Regards,
Manoj

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Received on Wed Nov 18 2009 - 12:12:35 ART