Sorry, access for this KB is restricted. Then, check following point and fix them.
1. Check if SNMP agent is enabled.
filer> options snmp.enable
If not, enable it by "options snmp.enable on"
2. Check if SNMP access is allowed.
filer> options snmp.access
If IP address of System Manager host is not listed, set it by "options snmp.access host=<IP address>"
3. Check filer's SNMP community name.
filer> snmp community
By default, "ro public" is displayed.
If you have modified SNMP community name, you need to modify registration on System Manager.
Edit C:\Users\<username>\NetApp\SystemManager\SystemManager.config and adjust snmp-community
element under storage-system element.