Limit bandwidth in cisco router with policy-map doesn't work

Question

I have a problem with my scenario in limiting bandwidth of ubuntu PC in GNS3 with class-map and policy-map. this is my topology in GNS3:

             -----------cisco-3725-router----------->Internet
            |
            |
            |
            |      
            |
         Switch
            |
          |   |
       |         |
    |               |
UBUNTU-PC         XP-PC

The R1 is a cisco 3725 router with c3725-adventerprisek9-mz.124-25d.bin image, and this is my configuration:

!

!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
!
resource policy
!
memory-size iomem 5
no ip icmp rate-limit unreachable
ip cef
ip tcp synwait-time 5
!
!
no ip domain lookup
!
!
class-map match-all UBUNTU_DW
 match access-group name UBUNTU_DW
class-map match-all UBUNTU_UP
 match access-group name UBUNTU_UP
!
!
policy-map UP
 class UBUNTU_UP
  police cir 32000 bc 4000 be 4000
    conform-action transmit 
    exceed-action drop 
    violate-action drop 
policy-map DW
 class UBUNTU_DW
  police cir 32000 bc 4000 be 4000
    conform-action transmit 
    exceed-action drop 
    violate-action drop 
!
!
interface FastEthernet0/0
 ip address 10.0.0.254 255.255.255.0
 ip nat inside
 ip virtual-reassembly
 duplex auto
 speed auto
!
interface Serial0/0
 no ip address
 shutdown
 clock rate 2000000
!
interface FastEthernet0/1
 ip address 216.65.200.143 255.255.255.0
 ip nat outside
 ip virtual-reassembly
 duplex auto
 speed auto
 service-policy input DW
 service-policy output UP
!
interface FastEthernet1/0
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
ip route 0.0.0.0 0.0.0.0 216.65.200.3
!
ip flow-top-talkers
 top 10
 sort-by bytes
!
no ip http server
no ip http secure-server
ip nat inside source list 1 interface FastEthernet0/1 overload
!
ip access-list extended UBUNTU_DW
 permit ip any host 10.0.0.51
ip access-list extended UBUNTU_UP
 permit ip host 10.0.0.51 any
!
access-list 1 permit 10.0.0.0 0.0.0.255
no cdp log mismatch duplex
!
!
control-plane
!
!
line con 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line aux 0
 exec-timeout 0 0
 privilege level 15
 logging synchronous
line vty 0 4
 login
!
!
end

The problem is the 32kbps limitaion for ubuntu does not work.

R1#sh policy-map interface fastEthernet 0/1
 FastEthernet0/1

  Service-policy input: DW

    Class-map: UBUNTU_DW (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group name UBUNTU_DW
      police:
          cir 32000 bps, bc 4000 bytes, be 4000 bytes
        conformed 0 packets, 0 bytes; actions:
          transmit
        exceeded 0 packets, 0 bytes; actions:
          drop
        violated 0 packets, 0 bytes; actions:
          drop
        conformed 0 bps, exceed 0 bps, violate 0 bps

    Class-map: class-default (match-any)
      905 packets, 812409 bytes
      5 minute offered rate 27000 bps, drop rate 0 bps
      Match: any

  Service-policy output: UP

    Class-map: UBUNTU_UP (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group name UBUNTU_UP
      police:
          cir 32000 bps, bc 4000 bytes, be 4000 bytes
        conformed 0 packets, 0 bytes; actions:
          transmit
        exceeded 0 packets, 0 bytes; actions:
          drop
        violated 0 packets, 0 bytes; actions:
          drop
        conformed 0 bps, exceed 0 bps, violate 0 bps

    Class-map: class-default (match-any)
      979 packets, 154180 bytes
      5 minute offered rate 7000 bps, drop rate 0 bps
      Match: any

Is there any wrong configuration? How can I apply this policy?

Solution

Sadly the NAT is happening before the policing I believe; thus making all traffic appear as the NAT'ted address instead of the internal address you have specified in your ACL / Class Map.

One idea is to mark the traffic coming in on FA0/0 matching the Ubuntu server with a DSCP value. Then police based on that DSCP value. That will solve your outbound issue.

For downstream I'm not quite sure why that policy is missing. I suspect the NAT issue again even though the order of operations seems to indicate it should be a non factor. http://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/6209-5.html

If it turns out to be NAT problem for downstream as well, then you can use an outbound policer on fa0/0 and have the same effect of choking the stream down.