Re: snmpEngineBoots

Hi Randy,

Interpretation of snmpEngineBoots in this way appears fine. But then, shouldn't
msgAuthoriativeEngineBoots start from 1 instead of 0?

Presently rfc3414 (USM) says
UsmSecurityParameters ::=
   ...
   msgAuthoritativeEngineBoots INTEGER (0..2147483647),
   msgAuthoritativeEngineTime INTEGER (0..2147483647),
   ...

Thanks,
Ann


Randy Presuhn wrote:

> Hi -
>
> > From: "Ann Lo" <[email protected]>
> > To: "C. M. Heard" <[email protected]>
> > Cc: <[email protected]>
> > Sent: Monday, May 05, 2003 1:24 PM
> > Subject: Re: snmpEngineBoots
> ...
> > Thanks for your information. I guess that this definition has originated
> > from the Unix system where the SNMP protocol can be operational when the
> > SNMP agent is down?
>
> No.
>
> > In many embedded systems, snmpEngineBoots would then start from 1 as these
> > systems would not respond to any SNMP requests until the SNMP agent is up
> > and running.
>
> No.  The snmpEngineBoots variable needs to persist, regardless of the
> operating system.  Whenever an SNMP engine starts up, the value needs to be
> incremented.  Consequently, if you ever want to see it on the wire with a
> value of 1, theinitial value (prior to the first time the SNMP engine is ever
> started) must be zero.  (This is just what Mike explained.)
>
> Randy
>
> > Regards,
> > Ann
> >
> >
> > "C. M. Heard" wrote:
> >
> > > On Fri, 2 May 2003, Ann Lo wrote:
> > > > Should snmpEngineBoots be initialized to 0 or 1? rfc3414 (USM)
> > > > says 0.
> > >
> > > That's the correct initial value.
> > >
> > > > rfc3411 says 1.
> > >
> > > More precisely, it says that's the minimum value that can be
> > > returned in respose to a Get-Request-PDU.
> > >
> > > > To be really consistent with both rfc's, the implemention could be as
> > > > follows:
> > > >
> > > >    * Set snmpEngineBoots to 0 when the SNMP agent is first installed.
> > > >    * Do not provide a MIB instance to snmpEngineBoots when it is 0.
> > >
> > > Note that the engine _cannot_ return any value until after it is
> > > booted at least one, so the second step is automatic.
> > >
> > > I seem to recall that this discussion has taken place on this list
> > > before.
> > >
> > > //cmh
> >