Rate limit ASR9k

[Juan Barco]

Hi,

I am trying to put a rate limit on a interface where I make the connection with my ISP, but I see it doesn't work, I always cosume more than 480 Mbps. Can you tell me what I am doing wrong?

policy-map BW_Internet
 class ALL_TRAFFIC
  police rate 480 mbps 
   conform-action transmit
   exceed-action drop

class-map match-any ALL_TRAFFIC
 match access-group ipv4 ALL_TRAFFIC 
 end-class-map

ipv4 access-list ALL_TRAFFIC
 10 permit ipv4 any any

interface Bundle-Ether4.3760
 description --Conexion_Internet_BGP--
 mtu 1700
 service-policy input BW_Internet
 service-policy output BW_Internet
 vrf INTERNET
 ipv4 address 190.131.xx.xx 255.255.255.252
 ipv6 address 2800:b70:800:100:x:x:x:x/127
 ipv6 enable
 encapsulation dot1q 3760

I am doing on a ASR9600, ios XR 4.1.0

[Emmanouil Patiniotakis · Accepted solution]

Please try:

policy-map BW_Internet
 class class-default
  police rate 480 mbps 
   conform-action transmit
   exceed-action drop

and tell us the results. in addition how above 480Mbps can you achieve/ becase there is aways a small amount of burst data. 

[Juan Barco]

Hi,

It worked, I would like to know, why it didn't work before. Before it up to 520 and stayed there, it was working the rate limit.

[Emmanouil Patiniotakis]

Honestly, I do not know...Did you have any non-ipv4 traffic?

[Juan Barco]

Yes, but not a lot.

[Michael Gehrmann]

Is there any advice on policer configuration?

I see the answer has a default burst calculation. What is the recommended burst config method/value calculation?

I'm conflicted over whether to use BC, BE or PIR? The guidelines and doco don't give clear explanations of each. I would normally give a 10% burst on another vendor device. I find without a little burst policers can be too aggressive on TCP flows.

Cheers

Mike

[Emmanouil Patiniotakis]

The formula for normal burst: (RATE-SPEED/8 / 20)

The formula for extended burst: NormalBurst + (RATE-SPEED/8 * 0.150)

e.g. for 20Mbps, your rate limit would be:

rate-limit out 20000000 125000 500000 conform-action transmit exceed-action drop