3Com 2928 User Guide - Page 144

Subtree mask A subtree OID used with a subtree mask defines a view subtree. A subtree mask is in hexadecimal format. After it is converted to binary bits, each bit corresponds to a node of the OID. z 1 means precise matching, that is, the OID of the MIB object to be accessed must be identical with the subtree OID. z 0 means wildcard matching, that is, the OID of the MIB object to be accessed can be different from the subtree OID. For example, provided the subtree mask 0xDB (11011011 in binary) and the subtree OID 1.3.6.1.6.1.2.1, their relationship is as shown in Figure 1-3. The view determined by them includes all the nodes under the subtree whose OID is 1.3.*.1.6.*.2.1, where * represents any number. Figure 1-3 Subtree OID and subtree mask z If the number of bits in the subtree mask is greater than the number of nodes of the OID, the excessive bits of the subtree mask will be ignored during subtree mask-OID matching. z If the number of bits in the subtree mask is smaller than the number of nodes of the OID, the short bits of the subtree mask will be set to 1 during subtree mask-OID matching. z If no subtree mask is specified, the default subtree mask (all Fs) will be used for mask-OID matching. SNMP Configuration Configuration Task List As configurations for SNMPv3 differ substantially from those for SNMPv1 and SNMPv2c, their configuration tasks are introduced separately as follows. Configuring SNMPv1 or SNMPv2c Perform the tasks in Table 1-1 to configure SNMPv1 or SNMPv2c: Table 1-1 SNMPv1 or SNMPv2c configuration task list Task Remarks Enabling SNMP Configuring an SNMP View Required The SNMP agent function is disabled by default. Optional After creating SNMP views, you can specify an SNMP view for an SNMP community to limit the MIB objects that can be accessed by the SNMP community. 1-3