In Cisco devices, the exact log message received with OSPF Database Overload, where large OSPF databases can cause memory issues and hinder OSPF neighbor formation, is as follows:

%OSPF-5-ADJCHG: Process <Process_ID>, Nbr <Neighbor_IP> on <Interface> from FULL to DOWN, OSPF Database Overload

Explanation of the log message:

  • %OSPF-5-ADJCHG: This log message indicates an OSPF adjacency change.
  • Process <Process_ID>: The log message includes the OSPF process ID for the specific OSPF instance running on the Cisco device.
  • Nbr <Neighbor_IP>: This part shows the IP address of the OSPF neighbor with whom the adjacency has changed.
  • on <Interface>: The log message specifies the name of the interface where the OSPF adjacency change occurred.
  • from FULL to DOWN: This section indicates that the OSPF adjacency transitioned from the FULL state (active adjacency) to the DOWN state (inactive adjacency).
  • OSPF Database Overload: The last part of the log message specifically indicates that the issue is related to a large OSPF database causing memory issues and hindering OSPF neighbor formation.

The log message serves as a notification to network administrators that a large OSPF database is causing memory overload, leading to the disruption of OSPF neighbor adjacencies. Addressing the OSPF Database Overload issue is critical to ensure stable OSPF neighbor formation and efficient network routing. This may involve optimizing OSPF database size, increasing memory resources, or adjusting OSPF configuration parameters as necessary.


A large OSPF database can impose significant memory burdens on Cisco devices, leading to performance issues and hindering OSPF neighbor formation. This article explores the challenges of OSPF Database Overload and provides a step-by-step solution using commands on Cisco devices to address and resolve this issue. By optimizing the OSPF database and managing memory resources effectively, network administrators can ensure seamless OSPF neighbor formation and improve network performance.

Understanding OSPF Database Overload and its Impact: The OSPF database stores link-state information about the entire OSPF network, including routing and topology details. When the database becomes excessively large due to the addition of numerous routes and interfaces, it can consume substantial memory resources on Cisco devices. Consequently, the OSPF process may struggle to maintain stable OSPF neighbor adjacencies, leading to degraded network performance and potential routing inconsistencies.

Solution for Resolving OSPF Database Overload:

Step 1: Check OSPF Database Size: Begin by assessing the size of the OSPF database on each router to identify the extent of the issue. Use the following command:

show ip ospf database summary

Examine the output to determine the size of the OSPF database and identify any excessively large LSAs (Link-State Advertisements).

Step 2: Optimize OSPF Network Design: Evaluate the network design and consider summarizing routes to reduce the number of LSAs in the OSPF database. Summarization can significantly decrease the database size while maintaining routing efficiency.

Step 3: Adjust OSPF SPF Timers: The SPF (Shortest Path First) algorithm is responsible for calculating the best paths in the OSPF network. By default, the SPF algorithm runs every five seconds after a change in the OSPF database. Consider adjusting the SPF timers to ensure optimal convergence without putting excessive strain on memory resources. Use the following command:

router ospf <Process_ID>
spf delay initial <Delay_Time> <Hold_Time>

Step 4: Limit OSPF Redistributions: Redistributions of routes from other routing protocols into OSPF can contribute to an increased OSPF database size. Limit redistributions only to essential routes to prevent unnecessary LSAs from overwhelming the database.

Step 5: Configure OSPF Database Filters: Implement OSPF database filters to control which routes and interfaces are included in the OSPF database. Filters help exclude unnecessary information and reduce database size. Use the following command:

router ospf <Process_ID>
database-filter all out

Step 6: Monitor OSPF Database Size: After implementing the solutions, regularly monitor the OSPF database size using the following command:

show ip ospf database summary

Verify that the OSPF database size has been optimized and remains within manageable limits.

Conclusion: Effectively resolving the issue of OSPF Database Overload is crucial for maintaining stable OSPF neighbor adjacencies and improving network performance. By following the step-by-step solution provided in this article and using the correct commands on Cisco devices, network administrators can successfully address and mitigate OSPF Database Overload. Optimizing the OSPF database, adjusting SPF timers, limiting redistributions, and applying database filters will ensure efficient OSPF neighbor formation and contribute to a robust and reliable OSPF network. Regular monitoring and proactive maintenance will further enhance network stability and support seamless data communication within the network.

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