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Customer Information Customer Company Name: (Internap) Customer Contact Information: ([email protected]) Customer Location: (All services with Level3 Communications) Original Ticket Number: SM Parent 1429209 Customer Impact: Outage Event Summary Outage location: IP North America, Trans-Atlantic and European Markets Ticket Create Date and Time: 10/21/2005 12:01 MDT Service Restore Date and Time: Between 10/21/2005 12:25 MDT to 10/21/2005 5:31 MDT depending on Location Total Duration: Varied by Location Event Description: A configuration update was applied to an edge router in Chicago as part of approved low risk maintenance activity. This validated and approved configuration change was applied to four other major markets with no impact. However; in this specific case the configuration was corrupted during the deployment process on this specific edge router. Upon load of the corrupted configuration, the device created an open-ended policy allowing this router's routes to be redistributed to OSPF. The engineering team immediately reverted to the previous saved configuration to mitigate route propagation. The rollback was followed by deliberate router isolation and complete device reload to ensure no stale LSAs (Link State Announcements), existed on the device and completed by 12:08 MDT. After reloading the edge router, the initial cause of the event was effectively mitigated. However, due to the number of flooded LSAs, other devices in the Level 3 network had difficulty fully loading the OSPF tables and processing the volume of updates. This caused abnormal conditions within portions of the Level 3 network. Manual intervention on specific routers was required to allow a number of routers to return to a normal routing state. Root Cause Analysis Committed redistribution of loopback statement in an erroneous state. Repair On devices with large number of adjacent neighbors a selective process of disabling interfaces on redundant paths or OSPF process restarts stabilized the affected portions to the network. Future Preventive Actions The Level 3 engineering team is currently analyzing the event in order to determine an appropriate action plan. Details of this specific plan will be available after the analysis is complete.
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