When an SNMP message is received by this entity, the community string in the message is compared with this string third. If it matches, read-only access is granted to all items in the MIB except community strings. (Community strings appear empty when read.) If it doesn't match, no access is granted, no response is sent back to the SNMP requester, and SNMP traps are sent to the SNMP trap receiver(s) if configured.