Owners manual

3Rack Power Filter: Using the Network Management Card
Watchdog Features
Overview
To detect internal problems and recover from unanticipated inputs, the Rack Power Filter uses internal,
system-wide watchdog mechanisms. When it restarts to recover from an internal problem, a System:
Warmstart event is recorded in the event log.
Network interface watchdog mechanism
The Rack Power Filter implements internal watchdog mechanisms to protect itself from becoming
inaccessible over the network. For example, if the Rack Power Filter does not receive any network traffic
for 9.5 minutes (either direct traffic, such as SNMP, or broadcast traffic, such as an Address Resolution
Protocol [ARP] request), it assumes that there is a problem with its network interface and restarts.
Resetting the network timer
To ensure that the Rack Power Filter does not restart if the network is quiet for 9.5 minutes, the Rack
Power Filter attempts to contact the default gateway every 4.5 minutes. If the gateway is present, it
responds to the Rack Power Filter, and the response restarts the 9.5-minute timer. If your application
does not require or have a gateway, specify the IP address of a computer that is running on the network
and is on the subnet. The network traffic of that computer will restart the 9.5-minute time frequently
enough to prevent the Rack Power Filter from restarting.