In this example, a cable between two routers that are running BGP services goes down. The example assumes that the cable connects two physical interfaces that each have one BGP protocol endpoint, which means that the cable supports one BGP session.
In this example, IP Availability Manager:
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Diagnoses a Cable Down problem.
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Generates a Cable DownOrFlapping event as an impact of the Cable Down problem.
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Exports the Cable Down problem and the Cable DownOrFlapping event to the Global Manager.
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Exports a Cable DownOrFlapping event-type status to Network Protocol Manager for BGP.
Network Protocol Manager for BGP:
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Receives the Cable DownOrFlapping event-type status from IP Availability Manager.
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Detects a disconnected BGP session for which the Cable DownOrFlapping event-type status is associated with the two physical interfaces that are underlying the disconnected BGP session.
As indicated in GUID-54856BF8-77ED-44E8-9747-13BDBF142F9D.html#GUID-54856BF8-77ED-44E8-9747-13BDBF142F9D___NPM_BGP_USER_CROSS_COR_EVENT_79289, Network Protocol Manager for BGPperceives the Cable DownOrFlapping event-type status as a problem-type status.
Network Protocol Manager for BGPthen:
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Generates a BGPSession Disconnected event.
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Generates a Cable DownOrFlapping problem.
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Correlates the BGPSession Disconnected event with the Cable DownOrFlapping problem and marks the event as an impact of the problem.
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Exports the Cable DownOrFlapping problem and the BGPSession Disconnected event to the Global Manager.
The Global Manager:
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Receives the Cable Down problem and the Cable DownOrFlapping event from IP Availability Manager.
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Receives the Cable DownOrFlapping problem and the BGPSession Disconnected event from Network Protocol Manager for BGP.
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Combines the Cable DownOrFlapping event from IP Availability Managerwith the Cable DownOrFlapping problem from Network Protocol Manager for BGPto form one notification that has two sources.
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Associates the Cable DownOrFlapping notification as an impact of the Cable Down notification.
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Associates the BGPSession Disconnected notification from Network Protocol Manager for BGPas an impact of the Cable Down notification.
What follows is a summary of the notifications that are created for the Cable Down problem, followed by a display in Notification Properties dialog box that shows a Cable Down problemthat shows how the Global Managerassociates the network and BGP events as impacts of the Cable Down problem:
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IP Availability Managerevents:
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Problem: Cable Down
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Event (impact): Cable DownOrFlapping
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Network Protocol Manager for BGPevents:
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Problem: Cable DownOrFlapping
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Event (impact): BGPSession Disconnected
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Global Managernotifications:
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Root cause: Cable Down
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Impacts: Cable DownOrFlapping and BGPSession Disconnected
Chapter 2, Viewing BGP Analysis Results and Topology,provides instructions on viewing detailed notification information.