Bandwidth monitoring

[Luigi Rizzo]

On Thu, Jun 26, 2003 at 07:05:57PM -0400, Robert Watson wrote:
...
> > that an ISP is likely to charge for and have the tables 'reaped every
> > now and then by a daemon to give a time dimension to the data.. 
> 
> Well, the case that this code was designed for was passive monitoring of
> many IPs over many systems (some of which have a large number of IP
> addresses, each to be separately billed).  I also wanted to specifically
> disqualify local traffic between the hosts, since that wasn't part of the
> billing structure.  You could certainly implement this using ipfw
> accounting, but only if you wanted to add one firewall rule for each
> matching case of interest (since we needed to separately measure), and you

just for the records, you can do counting on a per-host basis with
a single ipfw rule, using dummynet pipes:

	... rules to remove undesired traffic...
	ipfw add pipe 1 ip from ${my_subnet} to not ${my_subnet} in
	ipfw pipe 1 config mask src-ip 0xffffffff
	sysctl net.inet.ip.dummynet.expire=0

This of course requires that the traffic you are interested in
flows through the box where you are running the above ipfw config.

	cheers
	luigi