Dependency View of all devices connected to a switch or router

[David Casper]

Fairly straightforward question which I'm sure will have a not so straightforward answer. 

Goal is to be able to look at the dependency view of a switch and see all the connected devices. Specific use case that triggered this post is the ability to pull up a switchand see all the cameras using it and in reverse, look at a camera and see what switch it's going through.

Right now that data seems to be somewhat captures either in the 'device neighbors' related list or a device shows a connection to a switchport, but a holistic view does not appear to exist. 

When looking at servers you can easily follow the paths and see what interface it's going through, but that is also viewing that from the opposite end.

Is this possible with discovery? Does service mapping have to be utilized? 

Thanks!

[pavan9885]

Hi @StephanieLP ,

Please find the details below details

Discovery detects the physical connections, known as Layer 2, between network devices and between network devices and other components, such a servers, and stores this data for use by Dependency Views (BSM).

How Layer 2 Discovery Works

Discovery uses multiple probes to gather information about network adapters and their Layer 2 connections.

If Discovery finds a switch in a network, it triggers the SNMP - Switch - VLAN probe and the SNMP - Network - ARPTable probe. For every VLAN Discovery finds, it triggers the switch probes. If the switch has routing capabilities, Discovery triggers the SNMP - Routing probe to collect network adapter information. If Discovery finds a server, it triggers the appropriate Address Resolution Protocol (ARP) probe for that operating system.

During the discovery of a network device, the system creates records in the Router Interface [dscy_router_interface] table containing adapter information for that device. For SNMP-enabled devices, the information is gathered from a routing probe during the exploration phase. The Layer 2 protocol cache probe runs next to collect neighbor data from the device.

As Discovery gathers network information from the probes on a device, it populates the Device Neighbors [discovery_device_neighbors] table. In some cases, the neighbors of this device might not yet be known to the instance.

The neighbor's interface cannot be resolved to a record until Discovery eventually finds the neighbor's side of the relationship. When Discovery runs on the neighboring device, Discovery completes the information for the neighbor's interface for the original reporting device.

[pavan9885]

This will help too 

https://www.servicenow.com/docs/r/xanadu/it-operations-management/itom-visibility/c_Layer2Discovery....