Update interval for IOS MIB counters?

Dear readers! This time I really need your help (uncle Google and his relatives gave me only one relevant hit and even that doesn't work on 7200 or 1800).

I'm trying to implement an EEM applet that would detect traffic rate change using CISCO-CLASS-BASED-QOS-MIB. Everything would work perfectly ... if only IOS wouldn't update the MIB counters approximately every 10 seconds, not in real-time. Is anyone aware of a configuration command that would force the router to update these counters any faster?

11 comments:

  1. Hi Ivan,

    if the QOS MIB isn't your only option, and if the administrative overhead won't be too high, you might consider using an EEM applet tracking the rxload/txload parameters on an interface. these will give you a much granular results.

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  2. Thanks for the hint, but unfortunately I cannot do that. I need to identify when the real-time (for example voice) traffic starts and the only MIB variables I found so far are in the CBQoS MIB.

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  3. There is no way of doing this AFAIK, the data comes from the same place as the "show policy-map interface" which is updated every 10 seconds.

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  4. The "show policy-map interface" updates counters more often than every 10 seconds (although admittedly not in real-time). Unfortunately I need an SNMP variable to act upon, otherwise I would just execute the "show" command and extract the results.

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  5. the hidden command 'snmp-server hc poll 1000' is supposed to allow counters to be updated at 1sec

    -scott

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  6. Thanks, Scott! The command is accepted on a 1800 and a 7200, does not appear in the configuration (which I could easily fix :) and does not affect the MIB values :((

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  7. the units are actually hundredths of a second.

    try:
    snmp-server hc poll 100

    That will have IOS update the HC counters once per second. -WP

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  8. I see the exact same behavior, did you ever find a way to increase the rate of updates for this data?

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  9. There were a few useful suggestions (see above) that could work on specific platforms. I found nothing that would work well for me.

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  10. I guess I could have clarified but was in a rush. Cat6509, the previous undocumentated config (snmp-server hc poll xxx) does not give error but also does not affect what you and I are after. Oh well.

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  11. just can confirm that "snmp-server hc poll 100" works perfectly on 1841 platform ...

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Ivan Pepelnjak, CCIE#1354, is the chief technology advisor for NIL Data Communications. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.