Shaping and policing on Cisco
This post is about policing and shaping on Cisco routers and switches. This is a very big
topic so don't expect this post to cover everything. What I'm attempting to to is cover some
things that I found aren't explained very well by books or the Internets, while still being readable
for someone who hasn't read all the other stuff.
With QoS stuff there are always small differences in practice between the hardware implementations
but I won't go into that here.
Buckets
In both policers and shapers traffic that "conforms" is traffic that will be allowed through.
It will be allowed to go out to the interface (or in to it, if configured for incoming traffic)
if there are as many tokens in the Bc bucket as there are bytes in the packet.
If there are enough tokens then those tokens are removed from the bucket
and the packet is allowed through immediately. If there aren't
enough tokens in the bucket then the packet is n...
