Inbound Policier on the 3550 not accurate

From: Pierre-Alex (paguanel@hotmail.com)
Date: Fri Jun 02 2006 - 07:25:04 ART


I have the following problem: when applying a policy inbound on a trunk port I
have a discrepency of 40 K. See Verification section.
I do not have the problem when I am classifying via IP addresses. Has anyone
of you observed this? Any fix appart from changing the policing values?

Diagram:

Diagram :

r2 ------trunk -----Switch 1 -----R3
                             |
                           R6

r6 is in vlan 26
r3 is in vlan 23

-----------

Task:

R2 is pinging r6 and r3 at line rate with respective precedence of 1 and 5.
Limit traffic to r6 to 500Kb/s and
limit traffic to R3 at 1 Megabit/s. Drop the excess.

----------------

Configuration

mls qos

!

interface FastEthernet0/2
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 service-policy input police-in
 mls qos monitor dscp 8 40

class-map match-all cs1
  match ip dscp cs1
class-map match-all cs5
  match ip dscp cs5

policy-map police-in
  class cs1
    police 500000 93750 exceed-action drop
  class cs5
    police 1000000 187500 exceed-action drop

FastEthernet0/2
Ingress
  dscp: incoming no_change classified policed dropped (in bytes)
    8 : 262354422 51393408 0 0 0
    40: 102161400 0 0 0 0
Others: 494922022 445330872 362713564 0 294402306

--------------

Verification

r3#sh policy-map interface
 Ethernet0/0

  Service-policy input: inbound_measure

    Class-map: all_traffic (match-all)
      557654 packets, 363809819 bytes
      30 second offered rate 1046000 bps
      Match: access-group 1

    Class-map: class-default (match-any)
      0 packets, 0 bytes
      30 second offered rate 0 bps, drop rate 0 bps
      Match: any

r6#sh policy-map interface
 Ethernet0/0

  Service-policy input: inbound_measure

    Class-map: all_traffic (match-all)
      878931 packets, 449601296 bytes
      30 second offered rate 540000 bps
      Match: access-group 1

    Class-map: class-default (match-any)
      32687 packets, 2457912 bytes
      30 second offered rate 0 bps, drop rate 0 bps
      Match: any

!NB the policy-map on r3 and r6 do not do any actions. They are there only to
measure incoming traffic.
You can see that the 30 seconds rate is of by about 40K in both cases.



This archive was generated by hypermail 2.1.4 : Sat Jul 01 2006 - 07:57:31 ART