Data acquisition

Each probe uses a different method to acquire data. Which method the probe uses depends on the target system from which it receives data.

The probe regularly polls a list of hosts using ICMP packets in a similar way to the UNIX ping utility. It sends an ICMP packet to each host and then waits for a reply.

The probe generates events in the following conditions:

  • A host cannot be located by name or by IP address (this may represent a DNS problem)
  • A host fails to respond to the ICMP packets (for example, host down)
  • A host begins to respond after previously failing to respond (for example, host back up)
  • A new host is added to the list of hosts to be pinged
  • A host is removed from the list of hosts to be pinged
  • A host responds too slowly

The following topics describe how the probe acquires data: