This article provides information on how to determine the effectiveness of an ingress policer.

The effectiveness of an ingress policer cannot be determined b referring to the input BPS statistics of the ingress interface.

This is due to the policer action being performed after the ingress packet statistics are collected on the PFE.

To determine the policer effect, the egress interface statistics must be referenced. Here is an example of the input policer configuration:

1.6 Mb ingress traffic -> [1MB POLICER ] ge-0/3/0 ROUTER ge-0/3/6 [egress interface] -> 1Mb egress traffic

 interfaces {
    ge-0/3/0 {
        unit 0 {
            family inet {
                filter {
                    input POLICER;
                }
                address 10.10.10.2/24;
            }
        }
    }
    ge-0/3/6 {
        unit 0 {
            family inet {
                address 20.20.10.2/24;
            }
        }
    }
}
firewall {
    policer 1MB {
        if-exceeding {
            bandwidth-limit 1m;
            burst-size-limit 10k;
        }
        then discard;
    }
    filter POLICER {
        term 1 {
            then {
                policer 1MB;
                accept;
            }
        }
    }
} 

Input bytes:               79497298052 (1684696 bps)             [418732]
Output bytes:                        0 (0 bps)                        [0]
Input packets:               786969441 (2033 pps)                  [4044]
Output packets:                      0 (0 pps)                        [0]

Input bytes:                         0 (0 bps)                  [0]
Output bytes:              79239085176 (1002160 bps)            [7067428]
Input packets:                       0 (0 pps)                  [0]
Output packets:              784557469 (1226 pps)               [68698]