[c-nsp] SNMP question

[Sam Stickland]

Hi,

Gert Doering wrote:
> Hi,
>
> On Wed, Apr 04, 2007 at 03:46:27PM +0100, Sam Stickland wrote:
>   
>>> I've run some testing, and different Cisco platforms update the SNMP-viewable
>>> counters at different intervals.
>>>       
> [..]
>   
>> Thanks Gert, this is very helpful. I'm guessing then that there isn't 
>> any offical cisco documentation on this?
>>     
>
> Haven't ever seen anything - doesn't mean there is none, though.
>   
We had this reply from cisco. Far from conclusive, but useful none-the-less.

    Some snippets from the field:
     
    "Been through a bit of this on the 6500.  layer3 for instance if you
    poll for say multicast packets per S,G the mib is updated every
    70-90 seconds, same with a lot of stuff.  There are some knobs
    available that tune these say "ip mls multicast flow-stat-timer"
    allows you in decrease this time.  Layer3 stats are not generally
    updated very often due to the SNMP engine being on the MSFC,  layer2
    ASICs are a different story and are normally updated every second or
    2 this is because you can poll them directly."
     
    "Other (MLS) counters in 65/76 get updated on 15 second increments.
    But I don't know how that relates to the SNMP MIB.

    You will probably need to poll on 1 second increment (per counter)
    and see how often it changes in the presence of traffic.

    It seems that many of the MLS h/w counters are some kind of a
    periodic timer update.

    S/W counters should still be pretty much real-time.

    Anything in s/w IOS (87x-->7200) should be pretty much real-time AFAIK."

Sam