I’m using rate-limiting on an interface and the numbers are not adding up. I’m not finding any information on how the token buckets work for rate limiting, but am finding the information for CB policing. I started searching because I was seeing 22 packets at 66 bytes (528 bits) each pass through a rate-limit of 8k. At a rate limit of 8k there should only be 15 packets permited before the token bucket is exhaused. I expect 22 to pass due to the initial number of tokens being 12 000, but susequently only 15 should pass before another is dropped?? I think this rate is too low to even consider that the token buckets are receiving any tokens. All tokens replenished at Tc for the 8k policer are being used. Or are the Bc and Be token buckets replenished at Tc s well? I thought Bc and Be tokens were got the tokens that could not fit into the 8k token bucket. FYI: Tc replenishes a 1000 tokens.
Where am I going wrong?
R1(config-if)#do sh run int fa0/1
Building configuration…
Current configuration : 234 bytes
!
interface FastEthernet0/1
ip address 10.10.15.33 255.255.255.224
rate-limit input 8000 1500 2000 conform-action transmit exceed-action drop
duplex auto
speed auto
SW1#ping 10.10.15.33 siz 66 re 100
Type escape sequence to abort.
Sending 100, 66-byte ICMP Echos to 10.10.15.33, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!
!!!!.!!!!!!!!!!!!!!!!!!!!!!!.!
Success rate is 96 percent (96/100), round-trip min/avg/max = 1/3/9 ms