User guide

SNMP Configuring notification filters

iMG/RG Software Reference Manual (System Configuration)

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colons. Each octet is within the range 0x00 through 0xff. A zero-length OctetString is represented with a

dash (-).

snmpNotifyFilterType

is included or excluded. This object indicates whether the family of filter sub-trees defined by this entry are

included in or excluded from a filter.

snmpNotifyFilterStorageType

is nonVolatile, permanent, or readOnly.

The snmpNotifyFilterMaskfield allows filtering of MIB view at a finer granularity than that of the

snmpNotifyFilterSubtree and snmpNotifyFilterType pair alone. For instance, a filter can be

made to apply to one row of a table only (see the example below).

The value causes the corresponding snmpNotifyFilterMask to be a NULL string, which in turn allows all

objects ‘below’ the snmpNotifyFilterSubtree entry to be filtered.

The snmpNotifyFilterMask is built using octets that correspond to the OID being filtered.

For example, one may wish to restrict a filter of the ifTable to only the second row, all columns. The OID

for ifEntry.0.2 is: 1.3.6.1.2.1.2.2.1.0.2

The snmpNotifyFilterMask is a series of ones and zeros used for masking out parts of the filter.

A zero indicates a

WILD CARD (i.e. matches anything), and a one indicates an exact match must be made. So:

FIGURE 1-18 snmpNotifyFilterMask

would require an exact match on all fields except the table column (i.e. the 0 in ifEntry.0.2).

Using the above example, the bits of the snmpNotifyFilterMask would be grouped into bytes, and then

the right end padded with ones if necessary to fill out the last byte:

FIGURE 1-19 snmpNotifyFilterMask (continued)

OID

snmpNotifyFilterMask

1.3.6.1.2.1.2.2.1.0.2

1 1 1 1 1 1 1 1 1 0 1

1 1 1 1 1 1 1 1

byte 1

byte 2

hex value

original mask

padded with 1’s