[c-nsp] Usage Billing w/ Netflow / Implementation Pitfalls

[Simon Leinen]

Peter Rathlev writes:
> The lowest I can set "mls aging long" to is 64 seconds (Sup720), and
> a 1Gbps connection could hit 2^32 bytes in less than that, even at
> something like 75% use. And if we're talking 2^31 it's even worse.

The PFC3 will forcibly age out flows that get too close to the 2^32
(not 2^31) byte limit in spite of the "mls aging long" timer.

Because the aging process goes through the MLS flow table
periodically, you should still be able to wrap the counter if you're
fast enough.  4 Gigabytes in under 8 seconds should wrap pretty
reliably.  Not that I ever tried this.
-- 
Simon.