Monthly Archives: December 2018

SNMP and PRTG

The common mistake is to configure snmpd for v3 and forget to disable snmp v1/v2.

go to /etc/snmp/snmpd.conf and comment line with

“com2sec notConfigUser  default       public”

So full net-snmp installation and configuration should be something like:

  1. yum install -y net-snmp-utils net-snmp net-snmp-libs
  2. service snmpd status
  3. service snmpd stop
  4. net-snmp-create-v3-user -ro -A [password] -a MD5 -X snmpv3encPass -x DES snmpv3user
  5. comment line with “com2sec notConfigUser  default       public”
  6. service snmpd start
  7. configure PRTG or other monitoring tool
  8. chkconfig snmpd on
  9. snmptable -v 3 -u snmpv3user -l auth  -a MD5 -A [password] localhost usmUsertable
  10. snmpwalk -u snmpv3user -A [password] -a MD5 -l authnoPriv
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Windows useful commands to troubleshoot time issues

  • w32tm /query /status (see source and ReferenceId, in AD output should NOT be “Source: Local CMOS Clock” or “VM IC Time Synchronization Provider”, nor “Free-running System Clock” – maybe need to run below two commands)
  • net time /set
  • net stop/start w32time
  • to compare time on DCs for small companies with only several AD DCs – for example from powershell: “net time \\dc00″,”net time \\dc01″,”net time \\dc02″,”net time \\dc03″,”net time \\dc04” | ForEach-Object {cmd.exe /c $_}
  • for PDC emulator role:       
  • w32tm /config /manualpeerlist:pool.ntp.org /syncfromflags:manual /reliable:yes /update
  • to reset computer time settings in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters:
  • net stop w32time
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