The details shown below are based on the default settings. Editing this alert has no restrictions. The trigger and clear conditions can be changed to suit your needs.
Primary purpose: Notify when a network element has gone offline.
Possible causes for this alert include:
- Power outage or brownout
- Upstream switch or router on the network is also having issues
- Device misconfiguration
- ICMP traffic to device blocked
- Emergency maintenance
- Hardware malfunction
- Crash related to the operating system
- Device removed from network
Network elements include access points, controllers, firewalls, Layer 3 switches, packet processors, routers, stacks, and switches.
Repetitive alert pause condition
After 10 occurrences within 2 hours against a specific entity, pause the alert for 2 hours
Alert trigger condition
A network element has gone offline.
Alert clear condition
The network element is back online.
Action(s) to be taken
Check the status of the device to determine why it’s no longer online.
Additional information that the alert will provide:
This network element has gone offline. This may be due to a possible network configuration error.
- This means that the destination network is available, but the destination computer is not. The destination computer may be down. This message will appear mostly if the host is down; otherwise, offline. If the firewall is enabled, this message will appear. This shows we don't know how to send packets to the destination because none of the route tables can locate the correct path to send to.
This network element has gone offline. This may be due to a possible routing issue.
- This means that the destination network could not be found. When you try to ping an unknown network that is not available in the routing table, this message will appear. It shows when there is something wrong with the network configuration of the destination address. This may happen when a gateway is down, but the firewall shows offline.
This network element has gone offline.
- This means that the destination host unknown is sent from the destination network router. Meaning that the host is unknown. The ping does not know how to locate the target