IS-IS impact analysis overview

IS-IS failures, or apparent failures, that are detected by
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.
analyzes IS-IS and physical-transport failures to determine whether an IS-IS failure is indeed a root-cause problem, or simply a symptom (impact) of an underlying physical-transport root-cause problem.
When
detects an IS-IS failure, it checks for any physical-transport problem that might be causing the failure. If it does not find such a problem,
focuses its analysis on just the IS-IS domain and performs the root-cause analysis described in Chapter 3, “IS-IS Objects and their Failures.”
If it does find such a problem,
diagnoses the IS-IS failure as an impact and exports the underlying physical-transport problem and the IS-IS failure to the
Global Manager
. The
Global Manager
responds by adding the IS-IS failure as an impact of the underlying physical-transport root-cause problem.
IS-IS and global impact analysis shows the flow of information between the components in a
deployment to achieve IS-IS and global impact analysis.
IS-IS and global impact analysis
Status updates received from IP Availability Manager identifies the
IP Availability Manager
status updates to which
subscribes.
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
.
Card
Down
NetworkAdapter   Interface 1   Port
Disabled,
Down
NetworkConnection   Cable 1   TrunkCable
DownOrFlapping 2
UnitaryComputerSystem   Router 1   Switch   and so on
Unresponsive 2
imports status information from
IP Availability Manager
through a remote (proxy) accessor, as shown in Remote accessor operation for Network Protocol Manager for IS-IS.
Remote accessor operation for Network Protocol Manager for IS-IS
“Update object attributes” in Figure 17 corresponds to “Status updates” in IS-IS 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
causes
to import topology and status from the
IP Availability Manager
. The
provides the instructions for completing this task.