---
sourceDocument: Yokohama IT Operations Management
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/yokohama/it-operations-management

 Release :

    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama IT Operations Management

ft:clusterId :

    - itom

bundleId :

    - itom

workflow :

    - Technology


---

# Network switch and router

# Network switch and router discovery {#ariaid-title1}

* Release version: Yokohama
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 6 minutes to read

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](https://servicenow-prod.fluidtopics.net/CDLQ555JCwZ3FZ84_b4tRg#c_Layer2Discovery "Discovery can detect the physical connections, known as layer 2, between network devices.").  
Note:  
For information on Probe to Pattern migration see the knowledge article [KB0694477](https://support.servicenow.com/kb_view.do?sysparm_article=KB0694477).

## Prerequisites {#r_DataCollDiscoNWRouteAndSwitch__section_z3b_ksw_qbb}

* 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.
{#r_DataCollDiscoNWRouteAndSwitch__ul_ajb_ksw_qbb}

## System properties {#r_DataCollDiscoNWRouteAndSwitch__section_q15_gqw_qbb}

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 DefinitionProperties unless indicated otherwise. {#r_DataCollDiscoNWRouteAndSwitch__table_xdy_vfj_ks__entry__2}

| Property | Description |
|-|-|
| glide.discovery.L3_mapping | This creates IP Connecton::IP Connection relation between servers and network devices. * Type: string * Default value: true * Location: System Property \[sys_properties\] table {#r_DataCollDiscoNWRouteAndSwitch__ul_r15_gqw_qbb} |
| glide.discovery.max_concurrent_invocations_per_schedule | Sets a maximum number of scheduled invocations of the same Discovery schedule. It prevents a backlog of scheduled runs if Discovery does not finish before the next invocation is scheduled to run. The value is an integer that represents the max number of automated invocations of the same schedule that may proceed at one time. If the limit has been reached, subsequent scheduled invocations are canceled. A value of 0 or any negative number disables this property. * Type: integer * Default value: 3 * Location: Discovery DefinitionProperties {#r_DataCollDiscoNWRouteAndSwitch__ul_s15_gqw_qbb} Note: This property does not apply to schedules that have a 'Run after' configuration set to 'Even if canceled'. |
[ ]

{#r_DataCollDiscoNWRouteAndSwitch__table_xdy_vfj_ks}
For a list of properties used in discovery in general, see [Discovery properties](https://servicenow-prod.fluidtopics.net/6OmXtHd_W~setq24sqO8iw "Discovery properties allow you to control several aspects of the horizontal discovery process.").

## Credentials {#r_DataCollDiscoNWRouteAndSwitch__section_xph_5zp_qbb}

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](https://www.servicenow.com/docs/access?context=c_SNMPCredentials&version=yokohama&pubname=yokohama-platform-security&ft:locale=en-US) if they differ from the public community
string.  
Note:  
SSH is not supported for routers and switches, but is supported for [load balancers](https://servicenow-prod.fluidtopics.net/oFrrPczmFH9tXQq9sN9ZrA "Discovery can collect data about network routers, switches, and applications.").

## Classifier, pattern, and probes {#r_DataCollDiscoNWRouteAndSwitch__section_dfh_vvm_rz}

{#r_DataCollDiscoNWRouteAndSwitch__table_fzd_2yv_jz__entry__3}

| Classifiers | Trigger probes | Pattern |
|-|-|-|
| Standard Network Router Standard Network Switch | * Horizontal Pattern: launches patterns * SNMP-Routing\^ * DNS\* * SNMP-Identity\* * SNMP-Switch-Vlan\* * SNMP-Switching\* * SNMP - Network - ArpTable\* (Standard Network Switch only) {#r_DataCollDiscoNWRouteAndSwitch__ul_ixv_myv_jz} | [Network Router](https://servicenow-prod.fluidtopics.net/IEpAlpM1vSOXzl9OJ3jJjw "The Discovery and Service Mapping Patterns application uses the Network Router pattern to find network routers in your environment. Discovering some of these resources may require updating to the latest version of the Discovery and Service Mapping Patterns application from the ServiceNow Store.") [Network Switch](https://servicenow-prod.fluidtopics.net/Ij87Lh~p7ItSMwLqZpNJMw "The Discovery and Service Mapping Patterns application uses the Network Switch pattern to find network switches in your environment. Discovering some of these resources may require updating to the latest version of the Discovery and Service Mapping Patterns application from the ServiceNow Store.") |
[ ]

{#r_DataCollDiscoNWRouteAndSwitch__table_fzd_2yv_jz}

\*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](https://servicenow-prod.fluidtopics.net/F1AaGd2A7GKs7d9ZAQQp5w#t_AddHorizontalPatternProbe "To use a pattern for the identification and exploration phases of horizontal discovery, you must add the Horizontal Pattern probe to the classifiers for the CIs are you trying to discover.") 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

{#r_DataCollDiscoNWRouteAndSwitch__table_mmn_fhb_2gb__entry__3}

| Table name | Label/Field name | Source |
|-|-|-|
| cmdb_ci | Serial Number serial_number | SNMP, various MIBs |
| cmdb_ci | Manufacturer manufacturer | SNMP, RFC1213 MIB |
| cmdb_ci | Model ID model id | SNMP, RFC1213 MIB |
| cmdb_ci_ip_router | Name name |   |
| cmdb_ci_ip_router | Model ID model ID | SNMP, RFC1213 MIB |
| cmdb_ci_ip_router | Manufacturer manufacturer | SNMP, RFC1213 MIB |
| cmdb_ci_ip_router | Serial Number serial_number | SNMP, various MIBs |
| cmdb_ci_ip_router | IP Address ip_address | SNMP, IP MIB |
| cmdb_ci_ip_router | Description short_description |   |
| cmdb_ci_ip_router | Can route IP can_route | SNMP, IP MIB, BGP MIB |
| cmdb_ci_ip_router | Can switch IP can_switch | SNMP, dot1dBridge MIB |
| cmdb_ci_ip_router | Port port |   |
| cmdb_ci_ip_switch | Name name |   |
| cmdb_ci_ip_switch | Model ID model ID | SNMP, RFC1213 MIB |
| cmdb_ci_ip_switch | Manufacturer manufacturer | SNMP, RFC1213 MIB |
| cmdb_ci_ip_switch | Serial Number serial_number | SNMP, various MIBs |
| cmdb_ci_ip_switch | IP Address ip_address | SNMP, IP MIB |
| cmdb_ci_ip_switch | Description short_description |   |
| cmdb_ci_ip_switch | Can route IP can_route | SNMP, IP MIB, BGP MIB |
| cmdb_ci_ip_switch | Ports ports | SNMP, dot1dBridge MIB |
| cmdb_ci_ip_switch | Can switch IP can_switch | SNMP, dot1dBridge MIB |
| cmdb_ci_ip_switch | Can partition VLANs can_partitionvlans | SNMP, dot1dBridge MIB |
| cmdb_ci_ip_switch | Stack stack | SNMP, entPhysicalTable |
| cmdb_ci_ip_switch | Stack Mode stack_mode | SNMP, entPhysicalTable |
| cmdb_ci_netgear | Can route IP can_route | SNMP, IP MIB, BGP MIB |
| cmdb_ci_netgear | Can switch IP can_switch | SNMP, dot1dBridge MIB |
| cmdb_ci_netgear | Can partition VLANs cdscy_router_interface | SNMP, dot1dBridge MIB |
| cmdb_ci_netgear | Can Hub can_hub | SNMP, IP MIB |
| cmdb_ci_network_adapter | IP Address ip_address | SNMP, IP MIB |
| cmdb_ci_network_adapter | MAC Address mac_address | SNMP, IF MIB |
| discovery_device_neighbors | Neighbor Address neighbor_address | ciscoCdpMIB |
| discovery_device_neighbors | Neighbor ID neighbor_ID | ciscoCdpMIB, lldpMIB |
| discovery_device_neighbors | Neighbor Interface neighbor_interface | ciscoCdpMIB, lldpMIB |
| discovery_device_neighbors | Neighbor Source neighbor_source | ciscoCdpMIB, lldpMIB |
| discovery_device_neighbors | Origin Interface origin_interface | ciscoCdpMIB, lldpMIB |
| discovery_net_arp_table | IP Address IP_address | SNMP, IP MIB |
| discovery_net_arp_table | MAC Address mac_address | SNMP, IP MIB |
| discovery_switch_bridge_port_table | Interface Index interface_index | SNMP, dot1dBridge MIB |
| discovery_switch_bridge_port_table | Port port | SNMP, dot1dBridge MIB |
| discovery_switch_fwd_table | MAC Address mac_address | SNMP, dot1dBridge MIB |
| discovery_switch_fwd_table | Port port | SNMP, dot1dBridge MIB |
| discovery_switch_fwd_table | Status status | SNMP, dot1dBridge MIB |
| discovery_switch_fwd_table | VLAN ID vlan_id | SNMP, dot1dBridge MIB |
| discovery_switch_spanning_tree_table | Designated Bridge MAC designated_bridge_mac | SNMP, dot1dBridge MIB |
| discovery_switch_spanning_tree_table | Designated Root designated_root | SNMP, dot1dBridge MIB |
| discovery_switch_spanning_tree_table | Port port | SNMP, dot1dBridge MIB |
| discovery_switch_spanning_tree_table | Port Enable port_enable | SNMP, dot1dBridge MIB |
| discovery_switch_spanning_tree_table | Port State port_state | SNMP, dot1dBridge MIB |
| dscy_router_interface | Name name | SNMP, IP MIB |
| dscy_router_interface | Type type | SNMP, IP MIB |
| dscy_router_interface | Number number | SNMP, IP MIB |
| dscy_router_interface | IP Address ip_address | SNMP, IP MIB |
| dscy_router_interface | MAC Address mac_address | SNMP, IP MIB |
| dscy_route_interface | Destination Network dest_ip_network | SNMP, IP MIB |
| dscy_route_interface | Type type | SNMP, IP MIB |
| dscy_route_next_hop | Destination Network dest_ip_network | SNMP, IP MIB |
| dscy_route_next_hop | Type type | SNMP, IP MIB |
| dscy_route_next_hop | Next Hop next_hop_ip_address | SNMP, IP MIB |
| dscy_switchport | Type type | SNMP, dot1dBridge MIB |
| dscy_switchport | Status status | SNMP, dot1dBridge MIB |
| dscy_switchport | MAC Address mac_address | SNMP, dot1dBridge MIB |
| dscy_switchport | Port Number port_number | SNMP, dot1dBridge MIB |
| dscy_switchport | Interface Name interface_name | SNMP, dot1dBridge MIB |
| dscy_switchport | Interface Number interface_number | SNMP, dot1dBridge MIB |
| dscy_swtch_fwd_rule | MAC Address mac_address | SNMP, dot1dBridge MIB |
| dscy_swtch_fwd_rule | MAC Manufacturer mac_mfr | SNMP, dot1dBridge MIB |
| dscy_swtch_fwd_rule | Status status | SNMP, dot1dBridge MIB |
| dscy_swtch_fwd_rule | IP address ip_address | SNMP, dot1dBridge MIB |
| dscy_swtch_fwd_rule | Netmask netmask | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Base IP Address base_ip_address | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Base MAC Address base_mac_address | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Base Netmask base_netmask | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Type type | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Transparent transparent | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Source Route sourceroute | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Name name | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Status status | SNMP, dot1dBridge MIB |
| dscy_swtch_partition | Interface Number interface_number | SNMP, dot1dBridge MIB |
[ ]

{#r_DataCollDiscoNWRouteAndSwitch__table_mmn_fhb_2gb}
* **[Turn off collection of port data for SNMP network devices](https://servicenow-prod.fluidtopics.net/BRUliHCZASnFThmBWKWMWw)**   
  In some environments you may not want to collect the port data for SNMP network devices.

*[\>]: and then