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Monitor your networking configuration with Network Topology

You can use Network Topology to audit your networking configuration or troubleshoot networking issues. Network Topology provides a graph view of your networking infrastructure.

You can start using Network Topology by going to the Google Cloud console. No additional configurations are required.

Before you begin

Get an overview of Network Topology and its graph interface.

Get permissions

To view a Network Topology graph for a project, you must have at least read permissions for the project. For example, if you have the basic role roles/viewer, you can use Network Topology.

To view a Network Topology graph for multiple projects, you must have read access to the scoping project of a Cloud Monitoring metrics scope. You also need permissions to view Cloud Monitoring. No other resource level permissions are required.

For more information about the required permissions and roles, see Roles and permissions.

Add multiple projects to a single graph

Network Topology can visualize entities from multiple projects in a single graph. For example, in Shared VPC scenarios, you can view a graph that includes entities from the host and service projects.

To include multiple projects in a graph, see View metrics for multiple Cloud projects.

If you have a multi-project graph, you can aggregate entities by project.

The following sections describe how to use different features of the Network Topology interface such as filtering or navigating entity hierarchies.

Show or hide hierarchies and particular levels

You can select which hierarchy and their levels to show in the graph. You might want to do this to show or hide certain resource types. For example, you can clear the entire External clients hierarchy checkbox so that you see only the communication between your Google Cloud resources. In the graph, external clients and any traffic to and from them are hidden.

If you clear a specific level of a hierarchy, Network Topology hides it. For example, if you clear the Region network and Subnetwork checkboxes for VM instances, Network Topology shows instances by zone in each region, which is the next level in the hierarchy after networks and subnets.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the entities selection pane, select or clear a hierarchy checkbox to include or exclude an entire hierarchy, including their base entities.
  3. To toggle a specific level of a hierarchy, click More (icon for showing more options) next to the relevant hierarchy. You cannot clear some levels because they are required for visualizing entities in the graph.

Filter specific entities

Use filtering to show specific entities, such as a certain region, zone, or instance group. If you already know which resources you're investigating, use filtering to quickly view them in the graph. Network Topology shows the filtered entities and any peers that communicated with them. The filter feature lets you do the following:

  • Filter entities of any level in the hierarchy.

  • Use the asterisk (*) while specifying the names of entities to search and filter. For example, you can use the value *replica* to search for all entities containing replica in their name. You can place an asterisk anywhere within the pattern. For example, the Instance: www-*europe* filter matches both www-service-europe-f9vq and www-static-europe-a5hj instances.

  • Specify multiple filters. Network Topology shows any entity that matches at least one of the filters.

Filtering is case-insensitive.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the Filter field, select an entity type key such as Region or HTTPS load balancer.

    Network Topology shows filtering hints that correspond to entities present in the currently displayed graph. For example, if you clear the Load balancers checkbox in the topology configuration panel, Network Topology doesn't show filtering hints that are related to load balancers.

  3. Select a value for the filter such as us-east4 or my-load-balancer.

    Network Topology provides values that apply to your graph. For example, Network Topology doesn't show all Google Cloud regions for the Region filter. It shows only the regions that contain resources.

Navigate entity hierarchies

When you load a graph, all of the top-level entities are aggregated into their top-level hierarchies. You can expand an entity to view its lower-level entities. You can also collapse entities that you have expanded.

For example, you can expand a region to see all of the VPC networks that are in that region. The parent entity continues to visually wrap the lower-level entities. If, for example, you drag the region entity, the networks that are inside the region move with it.

For more information about entities and their hierarchies, see Entities in the Network Topology overview.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. Hover over an entity to display the Expand icon for expanding or Collapse icon for collapsing icon.

    If an entity is collapsed, Network Topology shows the Expand icon. If an entity is expanded, Network Topology shows the Collapse icon.

  3. Click the Expand or Collapse icon.

  4. In the configuration pane, to display only the traffic paths between top-level entities, such as regions, select the Show connections for child nodes only on focus checkbox.

    To view the traffic paths between lower-level entities, select or hold the pointer over the lower-level entities.

    To display all the traffic paths, clear the checkbox.

View metrics for traffic between entities

By default, Network Topology overlays throughput values on each connection so that you can quickly see the amount of traffic going between entities. You can also change which metric Network Topology overlays on connections. If the currently selected metric is not relevant for a connection, Network Topology does not overlay a value for that connection.

Metric values are based on the currently selected hour. For more information, see Data collection and freshness.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the entities selection pane, select a metric from the Edge metric drop-down menu.

  3. Navigate to a specific entity hierarchy to view traffic that is related to that entity.

    For example, if you want to view throughput between a zone and other regions, you must expand entities until you see that zone.

  4. Click the entity to highlight all of its traffic paths.

    Network Topology displays metric values for each connection that supports the currently selected metric.

View time series charts

Network Topology can show time series charts for some entities. For example, Network Topology can show the CPU utilization for an instance or the latency between a load balancer and one of its backends.

These charts show minute-by-minute values. Data for the charts are available to you within seven minutes after an activity.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. Navigate to a specific entity hierarchy to view traffic that is related to that entity.

    For example, if you want to see latency between a load balancer and other entities, you must expand entities until you see the load balancer.

  3. Click the entity to highlight all of its traffic paths.

  4. Click the metrics overlaid on the connection to view its details.

    Network Topology shows charts in the details pane. The information includes ingress and egress traffic between your selected entity and the connected entity. The metric values are for the selected hourly segment. If you're viewing the most recent segment, the metrics show real-time values.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. Find and expand the entity hierarchy until you see the entity that you want to view metrics for.

  3. Click the entity.

    Network Topology shows charts in the details pane. For example, for a VM instance, you can view the CPU utilization rate and the percentage of memory used. The metric values are for the selected hourly segment. If you're viewing the most recent segment, the metrics show real-time values.

Select an hourly segment

You can select a particular hourly segment to view the entities and their communication relationships that existed during that hour. When you first load a graph, Network Topology visualizes the most recently completed hour, but the metrics are from the last few minutes. For more information about data freshness, see Data collection and freshness.

To select different hourly segments, use the timeline and drag the slider to a particular hour.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the timeline, drag the slider to the hourly segment to view.

    Network Topology refreshes the graph with information for that segment.

Show only the current project or all projects

In multi-project scenarios, you can select the Show all projects in the Workspace checkbox to show all the projects in your metrics scope or only your current project.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the entities selection pane, select the Show all projects in the Workspace checkbox. To show only your current project, clear the checkbox.

    Network Topology redraws the graph and shows all the projects in your metrics scope or only your current project.

Aggregate entities by project

In multi-project scenarios, you can aggregate entities by project. That way, you can view and filter your resources by project and then by their standard hierarchies.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. In the entities selection pane, select Project aggregation.

    Network Topology redraws the graph and aggregates Google Cloud entities by project.

Use generated queries to retrieve detailed logs

If you have VPC Flow Logs enabled, you can look up detailed flows between an instance and another entity. If the logs are exported to BigQuery, you can copy queries that are generated by Network Topology and use them in BigQuery to view detail logs for a particular flow.

Network Topology generates queries for certain VM flows. If Network Topology overlays throughput metrics on a connection, it can generate a query for it. The generated query limits logs to the currently selected hourly segment.

Console

  1. In the Google Cloud console, go to the Network Topology page.

    Go to Network Topology

  2. Expand the entities that contain the instance to investigate.

  3. Click the instance to highlight all of its connections.

  4. Click the throughput metric to view the connection's details pane.

  5. In the details pane, under View flows in BigQuery, click Show instructions.

  6. If you have not already, follow the instructions under Before you begin to configure log exporting to a BigQuery sink and enable VPC Flow Logs. The instructions provide a table that lists the subnets that are relevant to the currently selected connection. The VPC Flow Logs status column indicates whether VPC Flow Logs is currently enabled.

  7. Follow the instructions under Running the query to copy the generated query and run it in BigQuery.

    BigQuery returns logs that you can use to further investigate or troubleshoot issues.

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