policing

Question 1

where can you apply policers?

Answer 1

either as part of a firewall policy

or in an interface within a protocol family. This makes it possible to police l2vpn and MPLS.

Question 2

what algo does this use?

Answer 2

token bucket. allows average throughput over time and supports configurable bursting

Question 3

Whats the recommended burst calc?

Answer 3

interface speed x time of burst.

eg, 100,000,000 bits per second interface for 5ms (5/1000s) = 500,000 bits, or 62,500 bytes

Question 4

what are the two policer fields?

Answer 4

bandwidth-limit
burst-size-limit

Question 5

how does this get configured?

Answer 5

Policer has a from then clause like all policy.

if the traffic is exceeding the limits the then action is carried out. If its not exceeding the limits no action is taken

if the policer then cause is NOT discard, the rest of the firewall filter takes effect