Multicast stats and bridging

[William Carrel]

In article 
<FE045D4D9F7AED4CBFF1B3B813C8533701D9B49F at mail.sandvine.com>,
 Alex Hoff <ahoff at sandvine.com> wrote:

> well I want my stats to match, so I can follow the data. For example, lets
> say I send 1000 multicasts packets from pc A through bridge B to pc C. I
> want the stats for multicasts packets to add up - Incoming 1000 mcast pkts
> on A-B interface and 1000 outgoing mcasts packets on the B-C interface. (And
> Im strictly talking about stack counters). Right now they are getting
> counted as unicast when they leave the bridge.  Does that make more sense?
> Sorry if I was not clear before.

The logic to record these packets differently would be needed to be 
inserted into src/sys/net/bridge.c:bdg_forward().

>From cursory reading of the code though, the destination is only 
recorded on incoming packets.  All outgoing packets forwarded out an 
interface are just counted as BDG_OUT.   To have BDG_MCAST counted both 
in and out packets would introduce some complexity to trying to make 
sense of those numbers.  Besides, unless the interface is full or some 
other error condition all multicast (and broadcast) packets will be 
bridged.  If an error results bdg_dropped will be incremented.

In sum, it isn't really "counted as unicast" at all.  It's simply 
counted as an outgoing packet, just like all the other outgoing packets.

-- 
William A. Carrel