Network switch and router discovery

Discovery identifies and classifies information about network switches and routers.

Network switches and routers often have very similar capabilities. It is very common for some switches known as Layer 3 switches to have IP routing. Larger routers with optional modules might accept switching modules. Because of these overlaps and the resulting ambiguity of a particular device's classification, Discovery collects the same data for both routers and switches, if it is available in any given device. For details on how Discovery collects data about connections between network devices and other components, see Layer 2 discovery.

Note: For information on Probe to Pattern migration see the knowledge article KB0694477.

Prerequisites

• The router or switch needs to have IP Address information.
• The system property glide.discovery.L3_mapping is set to true to discover routers and switches.
• The router or Layer 3 switch that provides the IP Address needs to have been successfully discovered with populated Exit Interface Routing Rules.
• If you must populate the [discovery_device_neighbors] table during horizontal layer 2 discovery of the bgp-enabled devices, set the BGP router exploration disable property to No. Notice that enabling this property can cause performance issues including out-of-memory issues on the MID Server.

System properties

You can configure many aspects of Discovery to work according to your personal preferences. The following properties apply to network routers and switches. To view the properties, navigate to Discovery Definition > Properties unless indicated otherwise.

For a list of properties used in discovery in general, see Discovery properties.

Credentials

Discovery explores many kinds of devices, such as switches, routers, and printers, using the SNMP protocol. SNMP Community Credentials do not include a user name, just a password, which is the community string. The default read-only community string for many SNMP devices is public, and Discovery will try that automatically. SNMPv3 credentials require a user name and a key, depending on the protocol selected. Enter the appropriate SNMP credentials if they differ from the public community string.

Note: SSH is not supported for routers and switches, but is supported for load balancers.

Classifier, pattern, and probes

*For new instances, these probes are inactive on the classifier. Discovery uses patterns for discovery.

^This probe remains active by default for the Standard Network Router classifier, even when Discovery uses pattern discovery.

To use patterns, verify that the correct pattern is specified in the horizontal pattern probe on the classifier. See Add the Horizontal Pattern probe to a classifier for instructions.

Discovering stacked switches

The Network Switch shared library supports Cisco stacked switches. The CI table for this is IP Switch [cmdb_ci_ip_switch]. Multiple switches in the stack are identified by the primary IP address. Each member of the stack is identified by a combination of elements, including the primary IP address, a name associated with the switch, and the stack mode. The relationship is created between a primary and all of the secondaries. The primary switch has all the fields listed in the table below. The secondary switch has name, serial_number, model_id, manufacturer, stack, and stack_mode.

Note: If all the ports on a switch are open for port 161, that switch will have multiple IPs (one for each port) but the serial number for all the ports is the same. The CI identification is performed based on the serial number, therefore the same record is updated every time instead of creating a new record.

Router and switch data

• Turn off collection of port data for SNMP network devices
  In some environments you may not want to collect the port data for SNMP network devices.

Parent Topic:Network device discovery