From: Peter Phaal (peter_phaal@inmon.com)
Date: 10/01/02
Marc,
Based on your suggestions I've updated SFLOW-DATAGRAM:
http://www.sflow.org/drafts/draft8/SFLOW-DATAGRAM.txt
The new text for sequence_number resetting is as follows:
struct flow_sample {
unsigned int sequence_number; /* Incremented with each flow sample
generated by this source_id.
Note: If the agent resets the
sample_pool then it must
also reset the sequence_number.*/
and:
struct counters_sample {
unsigned int sequence_number; /* Incremented with each counter sample
generated by this source_id
Note: If the agent resets any of the
counters then it must also
reset the sequence_number.
In the case of ifIndex-based
source_id's the sequence
number must be reset each time
ifCounterDiscontinuityTime
changes. */
Regards,
Peter
> Rather than ifLastChange, I think the more appropriate MIB
> variable to use
> would be ifCounterDiscontinuityTime (see RFC 2863, section 3.1.5 for
> details):
>
> ifCounterDiscontinuityTime OBJECT-TYPE
> SYNTAX TimeStamp
> MAX-ACCESS read-only
> STATUS current
> DESCRIPTION
> "The value of sysUpTime on the most recent
> occasion at which
> any one or more of this interface's counters suffered a
> discontinuity. The relevant counters are the specific
> instances associated with this interface of any
> Counter32 or
> Counter64 object contained in the ifTable or ifXTable. If
> no such discontinuities have occurred since the last re-
> initialization of the local management subsystem,
> then this
> object contains a zero value."
> ::= { ifXEntry 19 }
>
> Requiring the sFlow sample sequence numbers to be reset seems to be an
> equivalent solution, though. I suggest that it be documented
> with reference
> to ifCounterDiscontinuityTime. Essentially, for
> ifIndex-based data sources,
> if the value of ifCounterDiscontinuityTime changes, then the
> counter sample
> sequence number for the corresponding data source should be reset.
>
> Also, I think the phrase "affects the sample_pool" needs some
> clarification.
> If I understand the intent correctly, how about saying:
>
> Note: If the agent resets the
> sample_pool value
> then it must
> also reset the
> sequence_number.
>
This archive was generated by hypermail 2.1.4 : 10/01/02 PDT