SNMP-based Network Topology Mapping using SNMP v2/v3, LLDP/CDP and Custom Extensions

[Pandiya3]

Hi Team,

We are currently exploring a use case for SNMP-based network topology mapping in Dynatrace.

The goal is not only to collect SNMP metrics from network devices, but also to discover network devices and understand their relationships within the network topology.

For example, we would like to identify:

- Routers

- Switches

- Firewalls

- Access Points

- Servers

- Laptops

- Mobile Devices

- Printers

- Other connected network devices

and determine how these devices are connected to each other.

Example:

Router

|

Switch

|

+-- Laptop-01

+-- Laptop-02

+-- Mobile-01

+-- Printer-01

We are evaluating SNMP v2/v3 and topology-related MIBs such as:

- LLDP-MIB

- CDP-MIB

- BRIDGE-MIB

- IF-MIB

to discover device information, MAC address tables, neighbor information, and connected devices.

Our objective is to understand whether Dynatrace can discover these devices through SNMP and represent their relationships as a network topology map.

Questions:

1. Does Dynatrace support network topology discovery and visualization for SNMP-discovered devices?

2. Can SNMP Extension 2.0 be used to collect LLDP/CDP neighbor information and identify connected devices?

3. Can custom entities and topology relationships be created for network devices discovered through SNMP?

4. Will such relationships be visible in Smartscape or any other Dynatrace topology view?

5. If this is not natively supported, what is the recommended approach for implementing this use case?

We are currently in the investigation phase and would appreciate any guidance, best practices, or documentation references related to this requirement.

Thank you.

[p_devulapalli]

@Pandiya3  Yes, topology discovery should be possible, please read through the below for details on the supported extensions 

https://docs.dynatrace.com/docs/shortlink/snmp-autodiscovery-extension

[sujit_k_singh]

Hi @Pandiya3 

To direct answer to your questions:

1. Topology Discovery: Yes for core devices (Routers/Switches/Firewalls), but Dynatrace is not built to act as a full L2 switch-port mapper for end-user devices.

2. LLDP/CDP Support: Yes. Extension 2.0 can poll LLDP-MIB/CDP-MIB tables. The official SNMP Auto-Discovery Extension also has built-in neighbor discovery via LLDP, line is provided by @p_devulapalli 

3. Custom Entities & Relationships: Yes. You can define custom entity types and relationships (e.g., interface-to-neighbor) in your Extension 2.0 YAML (https://docs.dynatrace.com/docs/ingest-from/extensions/advanced-configuration/extension-customize)

4. Smartscape Visibility: Devices appear as network entities, but custom LLDP/CDP relationships are primarily visualized on Unified Analysis entity pages and queried via DQL in Notebooks/Dashboards, rather than classic host-centric Smartscape. (https://docs.dynatrace.com/docs/semantic-dictionary/model/smartscape/ext-network)

5. Recommended Approach: Use the SNMP Auto-Discovery Extension for core network infrastructure. If you require deep, end-user endpoint port mapping (laptops/printers), it is best practice to let an NMS handle the ARP crawling and sync the topology graph into Dynatrace using the Entities v2 API.

Thanks,

Sujit