From Net-SNMP Wiki

Why do I get "noSuchName" when asking for "sysUpTime" (or similar)?

Assuming that you do have access to this object, the most likely cause is forgetting the "instance subidentifier".

If you try walking the 'system' group, you should notice that all of the results have a number after the MIB object name. This is the "instance subidentifier" of that particular MIB instance.

For values from the sysORTable, this basically provides an index into the table, and should be very familiar. But the other values in the system group also have an instance number displayed. For non-table objects ("scalars"), this instance subidentifier will always be '.0', and it must be included when making a GET request.

Compare the following:

  $ snmpget -v1 -c public localhost sysUpTime
  Error in packet
  Reason: (noSuchName) There is no such variable name in this MIB.
  This name doesn't exist: system.sysUpTime
  $ snmpget -v1 -c public localhost sysUpTime.0
  system.sysUpTime.0 = Timeticks: (69189271) 8 days, 0:11:32.71
 

This is a little less obscure when using SNMPv2c or v3 requests:

  $ snmpget -v 2c -c public localhost sysUpTime
  system.sysUpTime = No Such Instance currently exists

   FAQ:Applications
   

1. How do I add a MIB?
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9. Why do I get "noSuchName" when asking for "sysUpTime" (or similar)?
10. Why do I sometimes get "End of MIB" when walking a tree, and sometimes not?
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