Setting discovery filters
Use filters to filter out devices either before discovery or after discovery. You can filter out devices based on a variety of criteria, including location, technology, and manufacturer. Filters provide additional restrictions to those defined in the scope zones.
About this task
- Prediscovery filters
- Prediscovery filters prevent discovered devices from being polled for
connectivity information.Note: Use prediscovery filters to configure scope for non-IP devices in the network, as shown in the examples below.
- Post discovery filters
- Post-discovery filters prevent discovered devices from being passed to
MODEL.Note: To ensure that alerts are not raised for interfaces that are excluded by the post discovery filter, you must set the
RaiseAlertsForUnknownInterfaces
variable. To this, perform the following steps:- Edit the $NCHOME/etc/precision/NcPollerSchema.cfg configuration file.
- Add the following line to the
file:
update config.properties set RaiseAlertsForUnknownInterfaces = 0;
To set the discovery filters:
Procedure
Configuring discovery filters
You can use a prediscovery filter to refine scoping. The prediscovery filter applies to chassis and interfaces, whereas the postdiscovery filter applies to all entities. Take care when defining postdiscovery filters so that you do not inadvertently filter out objects such as VPNs, cards, or subnets.
- Only pass non-IP devices to discovery
-
The following example filter is provided by default. It ensures that only non-IP devices are passed to discovery and interrogated further. This filter would exclude all IP-based devices.:
m_Protocol = 4
- Only pass non-IP devices to discovery and exclude the non-IP devices with a specified unique key
-
The following example insert ensures that only non-IP devices are passed to discovery and the non-IP devices that are passed must not include the specified string in their unique Element Management System (EMS) key.
( m_Protocol = 4 ) AND ( m_UniqueAddress NOT LIKE 'LONDON' )
- Exclude devices with a specified object ID
-
The following example shows a filter condition for a prediscovery filter that excludes devices with a specified object ID.
m_ObjectId not like '1\.3\.6\.1\.4\.1\.2\.3\.1\.'
- Restricting instantiation of a chassis based on entity name
-
The following example postdiscovery filter restricts instantiation of a chassis and its contents.
BASENAME != 'jane'
- Restricting instantiation of multiple chassis
-
The following example postdiscovery filter restricts instantiation of a chassis and its contents.
snmpSystem->SYSDESCR NOT LIKE ' device'