ModSnmp Manual v3.09 - 3. SNMP Users
The SNMP Users pages allow you to configure SNMP users and the SNMP engine ID.
Details of all defined users are displayed in the SNMP Users page.
As is conventional for SNMP agents, ModSnmp is configured by default to use 'public' as the user-name/community-string that it accepts in requests from SNMP managers. For security reasons, you should delete the 'public' user and use less well-known user names. If possible, use SNMPv3 and use an authentication protocol for all users.