Topology Filtering Workflow

The topology filter allows you to limit the nodes (devices) displayed in your topology map to a specific subset of nodes. This capability helps you control which nodes are recognized by Routing Director, enabling you to focus on critical nodes while excluding lower‑priority ones such as aggregation‑layer nodes or route reflectors.

Your network topology-related information is propagated to Routing Director either through dynamic topology (BGP-LS) or static topology (device collection and parsing).

However, topology filtering applies filter rules only to nodes learned through dynamic topology. It performs live filtering on the network topology using the node information received from BGP Monitoring Protocol (BMP) and BGP Link State (BGP‑LS). BMP collects dynamic topology data through BGP‑LS and provides it to Routing Director. For more details on topology acquisition, see Configuring Topology Acquisition Using BGP-LS.

Note: Nodes and links learned through alternate static method are not removed when you successfully apply a filter rule (for nodes and links) learned through dynamic topology.

Filtering the topology involves creating a set of filter rules. Each filter rule consists of a condition field to search on, a condition value to look for, a condition type to be applied (match or regular expression), and an action to be taken if the value is a match.

You can create a filter rule to control which nodes should appear on the topology map on the Topology page (Observability > Network > Topology). The filter rule at the top of the filter rules list holds the highest priority. Once a node matches a rule, the subsequent rules do not apply. For example, once a decision is made about the node (accept or reject), it will not change even if a rule below in the list provides the opposite result. The topology filter checks links and removes links that involve a rejected node, even if the rejected node is reporting information to the traffic engineering database.

Note: Filtered nodes and links are not permanently removed by Routing Director. However, live updates are not collected for such nodes and links. To permanently remove the nodes and links, you need to offboard the node (device).

If there are no filter rules configured, then the topology filter functions in transparency mode, allowing all the nodes to pass through the filter and appear on the topology map.

Benefits

Reduces visual clutter by limiting the displayed nodes to the ones relevant to your task.
Helps you to focus the monitoring and troubleshooting on a specific subset of devices.

To configure topology filtering:

Configure dynamic topology on the Peer Setting page (Management > Dynamic Topology > Peer Setting). When you configure dynamic topology, Routing Director captures real-time changes in your network. For more information, see About the Peer Setting Page
Create and apply filter rule on the Topology Filter page (Management > Dynamic Topology > Topology Filter). For more information, see About the Topology Filter Page.

Note: You must configure at least one filter rule for topology filtering to be active.
View the filtered nodes and links on the Topology page (Observability > Network > Topology).
The topology filter modifies the status of the node and the associated links.
- The nodes filtered by the topology filter display the value hyphen (-) in the Live column on the Device tab (Observability > Network > Topology > Device).
- The associated link displays the value Unknown in the Status column on the Link tab (Observability > Network > Topology > Link).
Note: For onboarded nodes (devices) that are filtered, live events and PCEP events data are not collected. Nodes that are not onboarded will not be displayed on the topology map.