PRO TIP: Monitoring Network Device Availability with NAM and DQL

[uros_djukic1]

Hi Dynatracers,
We are using Dynatrace Network Availability Monitors (NAM) to collect the availability of network devices through Ping/ICMP, DNS, and TCP checks. NAM supports ICMP, TCP, and DNS monitor types to validate the availability of hosts, devices, and services from a network perspective.

Example of Powerful DQL I use : 

timeseries availability = avg(dt.synthetic.multi_protocol.request.availability),
by: {
dt.entity.multiprotocol_monitor,
multi_protocol.request.target_address,
request.target_address
}
| fieldsAdd targetAddress = coalesce(request.target_address, multi_protocol.request.target_address)
| lookup [
fetch `dt.entity.network:device`
| expand dt.ip_addresses
| fields
deviceId = id,
deviceName = entity.name,
lookupIp = dt.ip_addresses
],
sourceField: targetAddress,
lookupField: lookupIp,
fields: { deviceId, deviceName }
| fieldsAdd monitorName = entityName(dt.entity.multiprotocol_monitor)
| fieldsAdd deviceName = coalesce(deviceName, "No matching network device")
| fields monitorName, deviceName, deviceId, targetAddress, availability

Result : 

Remark : 

Reachability is the key KPI because it measures whether the target network device or service is actually reachable from the monitoring location, regardless of the underlying protocol used: ICMP, DNS, or TCP.

Reachability (%) = average availability of NAM requests over the selected timeframe

Why Ping, DNS, and TCP Are Useful

• Ping / ICMP checks whether the device is reachable on the network.
  In simple terms: Can I reach the device?

• DNS checks whether the device or service name can be resolved correctly.
  In simple terms: Does the hostname resolve to the expected IP address?

• TCP checks whether a specific port is open and accepting connections.
  In simple terms: Is the expected service actually reachable on its port?

Conclusion : 

Ping validates network reachability, DNS validates name resolution, and TCP validates service-level accessibility. The DQL lookup then connects these checks back to the corresponding Dynatrace network device entity.

Hope it helps,
Cheers!