Set up threshold-based alarms for SNMP-monitored network devices so Cloudmon notifies your team or triggers automated actions the moment a device metric or interface breaches its defined limit.
Network devices monitored via SNMP expose a rich set of metrics through their assigned templates. Cloudmon automatically associates the appropriate template when a device is added, giving immediate access to CPU, memory, interface utilisation, and device-specific OID metrics. Cloudmon also automatically generates a sysUptime Reset alert whenever a device unexpectedly restarts and its uptime counter resets, helping you identify reboots, power issues, or hardware instability without any manual configuration.
There are two ways to configure alarm rules for network devices:
Each alarm is built around a simple IF/THEN model, where you select a metric, set a threshold, and define what happens when it is breached. Learn more.
Below are recommended alarm configurations for the most common network device monitoring scenarios:
| Use Case | Device Type | Metric | Suggested Threshold | Why |
| Router or firewall CPU saturated | Router, Firewall | CPU Utilisation | Above 80% for 3 intervals | High CPU on a core routing device causes packet drops, routing instability, and slow failover during path changes. |
| Uplink interface approaching capacity | Switch, Router | Interface Utilisation | Above 80% for 2 intervals | A saturated uplink causes congestion and latency for all downstream users before the link reaches 100% and drops traffic. |
| Switch memory running low | Switch | Memory Utilisation | Above 85% for 2 intervals | Low memory on a switch causes MAC table instability, dropped BGP or OSPF adjacencies, and increased packet processing errors. |
| Interface error rate spiking | Any SNMP device | Interface Error Rate | Above 1% for 2 intervals | Rising interface errors indicate a faulty cable, duplex mismatch, or a failing port that will cause intermittent packet loss before full failure. |
| Device unexpectedly rebooted | Any SNMP device | sysUptime Reset | Auto-detected by Cloudmon | Unplanned reboots on network devices can indicate power issues, hardware faults, or firmware crashes that need immediate investigation. |
| Firewall authentication failures | Firewall | Authentication Failure Count | Above 5 for 1 interval | Repeated authentication failures on a firewall are a strong indicator of a brute-force attack or misconfigured management credential. |
Once saved, all triggers for a device are listed in the Triggers table under the Alarm Rule section. Each row shows the trigger title, alarm severity, whether notifications are configured, whether a third-party service is linked, and whether a script is set to run. Triggers can be edited or deleted at any time using the action icons on the right.
To apply consistent alarm coverage across all devices of the same type without configuring each one individually, save the rule as a reusable template under Settings → Configurations → Alarm Rules and associate it to a group.