Users Guide

The LSA throttling timers are configured in milliseconds, with the interval time increasing exponentially until a
maximum time has been reached. If the maximum time is reached, the system, the system continues to
transmit at the max-interval until twice the max-interval time has passed. At that point, the system reverts to
the start-interval timer and the cycle begins again.
When you configure the LSA throttle timers, syslog messages appear, indicating the interval times, as shown
below for the transmit timer (45000ms) and arrival timer (1000ms).
Mar 15 09:46:00: %STKUNIT0-M:CP %OSPF-4-LSA_BACKOFF: OSPF Process 10,Router lsa id
2.2.2.2 router-id 2.2.2.2 is backed off to transmit after 45000ms
Mar 15 09:46:06: %STKUNIT0-M:CP %OSPF-4-LSA_BACKOFF: OSPF Process 10,Router lsa id
3.3.3.3 rtrid 3.3.3.3 received before 1000ms time
NOTE: The sequence numbers are reset when previously cleared routes that are waiting for the LSA
throttle timer to expire are re-enabled.
Router Priority and Cost
Router priority and cost is the method the system uses to “rate” the routers.
For example, if not assigned, the system selects the router with the highest priority as the DR. The second
highest priority is the BDR.
• Priority is a numbered rating 0 to 255. The higher the number, the higher the priority.
• Cost is a numbered rating 1 to 65535. The higher the number, the greater the cost. The cost assigned
reflects the cost should the router fail. When a router fails and the cost is assessed, a new priority
number results.
Open Shortest Path First (OSPFv2 and OSPFv3) 634