EIGRP impact analysis overview

EIGRP failures, or apparent failures, detected by Network Protocol Manager for EIGRP cannot be analyzed in isolation. Rather, those failures must be correlated with the physical-transport failures that are detected by IP Availability Manager in order to determine the root-cause problem that is underlying all observed symptoms. Network Protocol Manager for EIGRP analyzes EIGRP and physical-transport failures to determine whether an EIGRP failure is indeed a root-cause problem, or simply a symptom (impact) of an underlying physical-transport root-cause problem.

When Network Protocol Manager for EIGRP detects an EIGRP failure, it checks for any physical-transport problem that might be causing the failure. If it does not find such a problem, Network Protocol Manager for EIGRP focuses its analysis on just the EIGRP domain and performs the root-cause analysis described in Chapter 3, “EIGRP Objects and their Failures.”

If it does find such a problem, Network Protocol Manager for EIGRP diagnoses the EIGRP failure as an impact and exports the underlying physical-transport problem and the EIGRP failure to the Global Manager. The Global Manager responds by adding the EIGRP failure as an impact of the underlying physical-transport root-cause problem.

EIGRP and global impact analysis shows the flow of information between the components in a Network Protocol Manager for EIGRP deployment to achieve EIGRP and global impact analysis.

Figure 1. EIGRP and global impact analysis

Status updates received from IP Availability Manager identifies the IP Availability Manager status updates to which Network Protocol Manager for EIGRP subscribes.

Table 1. Status updates received from IP Availability Manager

Object	Problem-type status	Event-type status
1**Indentation indicates class hierarchy. 2**Perceived as a problem-type status by Network Protocol Manager for EIGRP.
Card	Down
NetworkAdapter   Interface 1   Port	Disabled, Down
NetworkConnection   Cable 1      TrunkCable		DownOrFlapping 2
UnitaryComputerSystem   Router 1   Switch   and so on		Unresponsive 2

Network Protocol Manager for EIGRP imports status information from IP Availability Manager through a remote (proxy) accessor, as shown in Remote accessor operation for Network Protocol Manager for EIGRP.

Figure 2. Remote accessor operation for Network Protocol Manager for EIGRP

“Update object attributes” in Figure 18 corresponds to “Status updates” in EIGRP and global impact analysis and in Status updates received from IP Availability Manager. Status updates represent changes to problem-type and event-type instrumentation attribute values.

Adding IP Availability Manager as a source to Network Protocol Manager for EIGRP causes Network Protocol Manager for EIGRP to import topology and status from the IP Availability Manager. The Network Protocol Manager Discovery Guide Supplement provides the instructions for completing this task.