hey guys!

i've been setting up a monitoring server with nagios + check_mrtgtraf
to monitor the throttle on some snmp switches by port. i left the
warning thresolds as they came by default, as this is a common
fastethernet network. 1Mbps for warnings, 5Mbps for criticals. the
server is up and running, generating the proper alerts.

but i got one problem. i need to differentiate between the traffic
that stays in our network and the traffic that goes out. i don't want
our inner traffic to be generating alerts, as we'd be overwhelmed with
mail notifications that really don't mean anything to us. is there a
way to differentiate between inner and outter traffic at this level -
on each switching port, on every switch- or any solution that could
come in handy for this problem?

thanks in advance for any comment that might lead the way.