Network availability monitoring

Dynatrace version 1.296+ ActiveGate version 1.295+

Network availability monitoring (NAM) allows you to monitor the availability of remote hosts or services over the network when an HTTP/HTTPS endpoint isn't available.

You can use NAM for infrastructure-related use cases or to deepen the root cause analysis for HTTP and browser monitors.

You can create synthetic network availability monitors of ICMP, TCP, or DNS type.

You can configure NAM monitors and access their performance results in Synthetic in latest Dynatrace. See create a NAM monitor to learn how to set up your monitor in Synthetic or via API.

NAM types

There are three types of network availability monitors.

  • ICMP—Sends pings with a configurable number of packets or size to validate if there's a network connection to the host or device. It also checks the quality of that connection.
  • TCP—Establishes a TCP connection to a particular port. It validates if a port is open and if it accepts TCP connections. It also checks if a host is available through the network.
  • DNS—Validates if a hostname can be resolved to an IP address.

To find out more about NAM types, see available script configuration properties.

Problems

Problems are created on the monitor level.

To receive alerts when problems are generated

  1. Edit the monitor.
  2. Go to Outage and Performance.
  3. Configure the problems and alerts you want to generate.

To analyze a problem

  1. In the Problems section of the preview panel, select Open in Problems app.
  2. In the Problems app, you'll see monitors affected by problems, where each problem consists of:
    • Affected steps—Expand the Step Id to see at least one of the following details request id, request type, failure reason and status message.
    • Affected requests—Expand the Request target you'll see request target address, request id, request type and failure reasons.
    • Affected locations.
    • Date of first failed execution.

Limitations

There are certain limitations when using network availability monitors. You can find out more about them below.

Number of requests

The maximum number of network activities executed per network availability monitor is 1,000. Network activity is a single DNS request, single TCP request, or single ICMP packet. Dynatrace may use multiple packets within a single ICMP request, if configured.

If a monitor uses a target filter, it might not be possible to precisely predict the number of requests in advance of execution (for example, when monitoring an entire host group or a subnet with a wide IP range). In such cases, the limit is applied when the target filter is resolved before the monitor's execution into the actual list of addresses.

The number of requests depends on the number of hosts matching the filter. For example, when monitoring an entire host group or filtering the monitored hosts using a subnet with a wide IP range.

Number of monitors

You can have up to 5,000 NAM monitors per environment. Other types of monitors don't contribute to this limit.

Deployment type

Network availability monitors are supported only on private Synthetic locations.

Network availability monitors are supported on containerized Synthetic-enabled ActiveGate deployments, but additional permissions are required for ICMP tests.

To enable ICMP request type for NAM execution

  1. In Dynatrace Hub Hub, search for Settings.
  2. In Settings, select and expand Web and mobile monitoring.
  3. In the Web and mobile monitoring section, select Private Synthetic Locations.
  4. Select Add Kubernetes location.
  5. Configure your location and make sure to turn on Enable ICMP request type for Network Availability Monitors execution.

ICMP monitors use the ping executable, which requires the CAP_NET_RAW capability set for the container executing the requests (synthetic-vuc). Additionally, the allowPrivilegeEscalation property of securityContext for this container has to be set to true, because the process that launches the ping executable doesn't have the required privileges set by default.

The entire securityContext for the synthetic-vuc container with enabled network availability monitors should look as follows.

securityContext:
  readOnlyRootFilesystem: true
  privileged: false
  allowPrivilegeEscalation: true
  runAsNonRoot: true
  capabilities:
    drop: ["all"]
    add: ["NET_RAW"]

Use of proxy

Network availability monitors do not support the use of proxy servers. Ensure that your network configuration allows direct access to the monitored endpoints without routing through a proxy.