Network router discovery using patterns

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.

Request apps on the Store

Visit the ServiceNow Store to view all the available apps, and for information about submitting requests to the store. For cumulative release notes information for all released apps, see the ServiceNow Store version history release notes.

To learn about network routers and their versions that you can discover, refer to Detailed information on products discovered by ITOM Visibility.

For information on probe-based network switch and router discovery, see Network switch and router discovery.

Prerequisites

Verify that the applications are up to date

• Discovery and Service Mapping Patterns
• Visibility Content

Verify IP address information

The router must contain IP address information for successful discovery.

Verify that exit interface routing rules are configured and reachable

The router that provides the IP address must have exit interface routing rules configured and be reachable for successful discovery.

Create SNMP credentials

Create SNMP Community Credentials or SNMPv3 credentials. For more information, see SNMP credentials.

Configure properties for router discovery

Navigate to sys_properties.list and verify that the glide.discovery.L3_mapping system property is set to true.

You can configure these additional properties for network router discovery.

Property	Description
glide.discovery.max_concurrent_invocations_per_schedule	Sets a maximum number of scheduled invocations for the same Discovery schedule. It prevents a backlog of scheduled runs if Discovery does not finish before the next one starts. The value is an integer that represents the max number of automated invocations that can run concurrently for the same schedule. If the limit is reached, subsequent scheduled invocations are canceled. A value of 0 or any negative number disables this property. Type: integer Default value: 3 Location: Discovery Definition > Properties 注: This property does not apply to schedules that have a 'Run after' configuration set to 'Even if canceled'.
glide.discovery.bgp_router_disable	Disables running the SNMP – Routing pattern when discovering a router running the BGP protocol. If you must populate the Device Neighbors [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. Type: true | false Default value: true Location: Discovery Definition > Properties

Data collected by Discovery during horizontal discovery

Discovery populates the data in the CMDB when running the Network Router pattern.

表 : 1. IP Router [cmdb_ci_ip_router]

Field	Description
Name [name]	Name of the router.
Model ID [model_id]	Hardware model ID of the router.
Manufacturer [manufacturer]	Router manufacturer.
Serial number [serial_number]	Unique hardware serial number of the router.
IP Address [ip_address]	IP addresses assigned to interfaces.
Description [short_description]	Device description.
Can route IP [can_route]	Indicates whether the IP pockets can be routed between networks. Possible values are true or false.
Can partition VLANs [can_partitionvlans]	Indicates whether the local area network (LAN) can be partitioned. Possible values are true or false.
Can switch IP [can_switch]	Indicates whether a network device has Layer 2 switching capabilities. Possible values are true or false.
Physical interface count [physical_interface_count]	Number of physical interfaces.
Ports [ports]	Individual network interface (physical or logical) used to connect devices such as computers, servers, access points, or uplinks to switches or routers.
Discovery Protocol ID [discovery_proto_id]	Unique identifier of the device participating in the Cisco Discovery Protocol (CDP) or Link Layer Discovery Protocol (LLDP) protocol.
Discovery Protocol Type [discovery_proto_type]	Protocol type. Possible values are CDP or LLDP.

表 : 2. IP Address [cmdb_ci_ip_address]

Field	Description
IP Address [ip_address]	IP address of the router.
Netmask [netmask]	Netmask of the router.
Nic [nic]	References the Network Adapter [cmdb_ci_network_adapter] table.

表 : 3. Network Adapter [cmdb_ci_network_adapter]

Field	Description
Name [name]	Name of the network adapter.
IP Address [ip_address]	IP address of the network adapter.
Netmask [netmask]	Netmask of the network adapter.
MAC Address [mac_address]	MAC address of the network adapter.
Alias [alias]	User-assigned name for the network adapter.
Configuration Item [cmdb_ci]	References the IP Router [cmdb_ci_ip_router] table.

表 : 4. DNS Name [cmdb_ci_dns_name]

Field	Description
Name [name]	Name of the Domain Name System (DNS).
IP Address [ip_address]	IP address of the DNS.

CI relationships

Discovery creates these relationships to support the network router discovery.

CI	Relationship	CI
Exit Interface Routing Rule [dscy_route_interface]	References	IP Router [cmdb_ci_ip_router]
IP Address [cmdb_ci_ip_address]	References	Network Adapter [cmdb_ci_network_adapter]
IP Router [cmdb_ci_ip_router]	Contains::Contained by	Switch Forwarding Rule [dscy_swtch_fwd_rule]
IP Router [cmdb_ci_ip_router]	Contains::Contained by	Switch Partition [dscy_swtch_partition]
IP Router [cmdb_ci_ip_router]	Contains::Contained by	Switchport [dscy_switchport]
IP Router [cmdb_ci_ip_router]	Owns::Owned by	IP Address [cmdb_ci_ip_address]
IP Router [cmdb_ci_ip_router]	Owns::Owned by	Network Adapter [cmdb_ci_network_adapter]
IP Router [cmdb_ci_ip_router]	Uses::Used by	Exit Interface Routing Rule [dscy_route_interface]
IP Router [cmdb_ci_ip_router]	Uses::Used by	Next Hop Routing Rule [dscy_route_next_hop]
IP Router [cmdb_ci_ip_router]	Uses::Used by	Router Interface [dscy_router_interface]
Network Adapter [cmdb_ci_network_adapter]	Owns::Owned by	IP Address [cmdb_ci_ip_address]
Network Adapter [cmdb_ci_network_adapter]	References	IP Router [cmdb_ci_ip_router]
Network ARP Table [discovery_net_arp_table]	References	IP Router [cmdb_ci_ip_router]
Next Hop Routing Rule [dscy_route_next_hop]	References	IP Router [cmdb_ci_ip_router]
Router Interface [dscy_router_interface]	References	IP Router [cmdb_ci_ip_router]
Serial Number [cmdb_serial_number]	References	IP Router [cmdb_ci_ip_router]
Switch Bridge Port Table [discovery_switch_bridge_port_table]	References	IP Router [cmdb_ci_ip_router]
Switch Forwarding Rule [dscy_swtch_fwd_rule]	References	IP Router [cmdb_ci_ip_router]
Switch Forwarding Table [discovery_switch_fwd_table]	References	IP Router [cmdb_ci_ip_router]
Switch Partition [sdcy_swtch_partition]	References	IP Router [cmdb_ci_ip_router]
Switch Spanning Tree Table [discovery_switch_spanning_tree_table]	References	IP Router [cmdb_ci_ip_router]
Switchport [dscy_switchport]	References	IP Router [cmdb_ci_ip_router]