HKLM\SYSTEM\CurrentControlSet\Services\SNMP\Parameters\
The ValidCommunities subkey stores a list of the communities defined to the SNMP service.
To SNMP, a community is a group of hosts (servers, workstations, hubs, and routers) that are administered together by SNMP. An SNMP agent accepts requests only from management systems within the communities it recognizes and and only when the requested operation is allowed by the permissions established for the community.
A community name is a network password shared by the hosts in the community.
Each entry in the ValidCommunities subkey represents one community that you identified to SNMP. The entry name is the same as the community name and the value of the entry is bitmask specifying the permissions of the community. All entries have the REG_DWORD data type.
For example,
| ROCommunity | REG_DWORD | 0x4 |
| RWCommunity | REG_DWORD | 0x8 |
constitutes a list of communities as stored in the ValidCommunities subkey.
To change the value of this entry use the Services snap-in. Right-click SNMP Service, then click Properties.