Information About OSPF Link-State Database Overload Protection
The OSPF Link-State Database Overload Protection feature allows you to limit the number of nonself-generated link-state advertisements (LSAs) for a given Open Shortest Path First (OSPF) process or OSPFv3 process. Excessive LSAs generated by other devices in the OSPF domain can substantially drain the CPU and memory resources of the device.
The OSPF Link-State Database Overload Protection feature is applicable to OSPF, OSPFv2 and OSPFv3.
Benefits of Using OSPF Link-State Database Overload Protection
The OSPF Link-State Database Overload Protection feature provides a mechanism at the OSPF level to limit the number of nonself-generated LSAs for a given OSPF process. When other devices in the network have been misconfigured, they may generate a high volume of LSAs, for instance, to redistribute large numbers of prefixes. This protection mechanism prevents devices from receiving a large number of LSAs and therefore experiencing CPU and memory shortages.
Overview of OSPF Link-State Database Overload Protection
When the OSPF Link-State Database Overload Protection feature is enabled, the device keeps a count of the number of nonself-generated LSAs that it has received. When the configured threshold number of LSAs is reached, an error message is logged. When the configured maximum number of LSAs is exceeded, the device sends a notification. If the count of received LSAs is still higher than the configured maximum after one minute, the OSPF process takes down all adjacencies and clears the OSPF database. In this ignore state, all OSPF packets received on any interface that belong to this OSPF process are ignored and no OSPF packets are generated on any of these interfaces. The OSPF process remains in the ignore state for the time configured by the ignore-time keyword of the max-lsa command. Each time the OSPF process gets into an ignore state a counter is incremented. If this counter exceeds the number of times configured by the ignore-count keyword, the OSPF process stays permanently in the same ignore state and manual intervention is required to get the OSPF process out of the ignore state. You can get the OSPF process out of the permanent ignore state by restarting the OSPF process. The ignore state counter is reset to 0 when the OSPF process remains in the normal state of operation for the amount of time that was specified by the reset-time keyword. If the warning-only keyword of the max-lsa command is configured, the OSPFprocess will send only a warning that the LSA maximum has been exceeded.