ok, thanks for the replay, I will try that

question, how do you know it is the "ciscoMemoryPoolMIB" ? 

if I debug the SNMP the queue is filling up with UDP traffic, (snmp-get's) from my NMS server....

Feb 28 11:36:22: SNMP: Packet received via UDP from 10.x.x.x on Dialer1
process_mgmt_req_int: UDP packet being de-queued

regards Pascal

I don't know its that exact bug fix, im going by the general error .....%SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input queue full..........

There are multiple bugs registered for this alert on multiple versions of software , this was one pf the fixes that resolved it on certain router platforms

You can check your release notes online on Cisco website to see if there is an open caveat/bug for that version , it may or may not be there , if not you will have to try the fixes that are available or raise a case with Cisco and get them to give you the exact ID of the bug and go from there

Symptoms: SNMP stops to respond. The following message is generated:

"%SNMP-3-INPUT_QFULL_ERR: Packet dropped due to input queue full

This issue is affecting the CISCO-MEMORYPOOL-MIB instead.

Conditions: These symptoms are observed under the following conditions:

ok, thank's for the answer, I thought there is a command to see witch "MIB" is generating this error and filling up the snmp-queue. 

yes, I have checked the "bug's" but could not find a corresponding hardware-plattform oder IOS-release at all...

so I think I have to open a case....

thanks anyway

regards Pascal 

You should be able to see it if you debug the snmp traffic , I haven't hit the alert so I have not had to investigate it that far before

#debug snmp ?
  cef              SNMP CEFMIB Errors
  cifextmib-err    SNMP CISCO-IF-EXT-MIB Errors
  cifextmib-trace  SNMP CISCO-IF-EXT-MIB Trace
  detail           SNMP Detail
  headers          SNMP packet headers
  ifmib-err        SNMP IFMIB Errors
  ifmib-trace      SNMP IFMIB Trace
  imagelevel       SNMP License Imagelevel MIB
  mib              MIB commands
  overhead         SNMP overhead
  packets          SNMP packets
  requests         SNMP requests
  sessions         SNMP sessions
  sync             SNMP state synchronization
  timers           SNMP timer activity
  tunnel-mib       SNMP tunnel-mib debug

I have tryed: 

SNMP:
SNMP Detail debugging is on
SNMP IF-MIB Errors debugging is on
SNMP IF-MIB Trace debugging is on
SNMP CISCO-IF-EXT-MIB Errors debugging is on
SNMP CISCO-IF-EXT-MIB Trace debugging is on
SNMP packet debugging is on
SNMP MGR requests debugging is on

but could not find out where the problem could be located....

Why not try the current recommended ios version these are usually the least bug effected , it may fix it save you opening a case as they will probably advise something along those lines anyway unless they have another workaround

c880data-universalk9-mz.154-3.M7.bin

https://software.cisco.com/download/release.html?mdfid=283122091&reltype=latest&relind=AVAILABLE&release=15.6.3M1&softwareid=280805680&sortparam=

thanks for the answer, I though about that as well, but lisp is not running like I need it... 

I may have found something... after I installed the IOS 156.3M1 the MIB on the router may have changed (this happen), but my NMS is still trying to get the "old" mib-oid-index's. 

so if I reload the "problem-routers" and re-discover again, the snmp-queue stand's on 0/1000, and no dopping packets.

I will test some more, this could be the problem...

-- thanks for the discussion --