Subject: Re: Resetting ip, icmp etc statistics
To: None <>
From: Liam J. Foy <>
List: tech-net
Date: 04/01/2006 11:24:31
On 16:01, Fri 31 Mar 06, wrote:
> In message <20060331215119.GA649@nikita>, "Liam J. Foy" writes:
> >On 22:54, Fri 31 Mar 06, Havard Eidnes wrote:
> >> "Real" routers where statistics is normally collected using SNMP
> >> and who also have this "clear counters" function do this IMO the
> >> right way, i.e. by checkpointing the base level for the counters
> >> and only displaying the difference compared to this base level
> >> when commands equivalent to "netstat" are run.
> >
> >Could you explain this approach a little more to me please? How and when
> >are the 'checkpoints' made?
> The kernel keeps two sets of counters: a set of monotonic counters,
> and a duplicat set holding the values at the point when a
> "zeroization" was last requested. A 'zeroization' (e.g., ifconfig -z,
> or the proposed reset for our BSD per-protocol "mib" counters) would
> no longer zeroize the monotonic counters, but would instead copy the
> current value of the monotonic counters to the duplicate,
> "count-at-last-zeroization" counter set.
> Showing monotonic-since-boot (or since last wrap, which given that
> we've had 64-bit counters for years now, is a very rare case) then
> becomes a user-interface presentation issue: does the UI tool show
> you the raw monotonic counters, or does it instead show
> 	(monotonic count - counter-value-at-last-zeroization)?

Yeah, this is really the issue I see. Maybe have enough option to
netstat which will show the difference and leave the default behaviour
showing the raw values. I'm not sure whether thats a little more

		Liam J. Foy