This monitor generates an alert when the agent detects that the network adapter has been disconnected from the network and no longer has network connectivity.
If the computer has multiple network adapters, the alert may arrive before network connectivity for the effected adapter has been reestablished. However, remote clients and applications may still have difficulty accessing resources on the computer despite the other adapter or adapters. In addition, the local computer may not be able to access some network resources.
Your computer's network adapter lost its connection to the network.
The adapter's connection to the network can be lost if you remove a network cable from your network adapter or if you are roaming between wireless access points with a mobile system. Other possible causes include network issues, firewall issues, or a malfunction of the network adapter or its driver.
If your computer is connected to the network by cable, confirm that the cable is plugged in properly. If you have a wireless network connection, confirm that you have a signal and the proper credentials for the wireless network.
If the network connection is working properly, check the following possible causes and take corrective action:
The network is down. Attempt to ping or traceroute to the host.
The firewall on your server is blocking network broadcast traffic.
Your computer's network adapter or driver is not functioning correctly. Login to the system as root and type 'ifconfig -a' to view all available network interfaces.