Brocade Communications Systems ICX 7250 series, Руководство по настройке

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NOTE
This option affects only imported, type 5 external LSA routes. A single type 5 LSA is generated and flooded throughout the
autonomous system for multiple external routes. Type 7-route redistribution is not affected by this feature. All type 7 routes will
be imported (if redistribution is enabled). To summarize type 7 LSAs or exported routes, use NSSA address range
summarization.
SPF timers
The device uses an SPF delay timer and an SPF hold-time timer to calculate the shortest path for OSPFv2 routes. The values for both
timers can be changed.
• SPF delay: When the device receives a topology change, it waits before starting a Shortest Path First (SPF) calculation. By
default, the device waits zero seconds. You can configure the SPF delay to a value from 0 through 65535 seconds. If you set
the SPF delay to 0 seconds, the device immediately begins the SPF calculation after receiving a topology change.
• SPF hold time: The device waits a specific amount of time between consecutive SPF calculations. By default, it waits zero
seconds. You can configure the SPF hold time to a value from 0 through 65535 seconds. If you set the SPF hold time to 0
seconds, the device does not wait between consecutive SPF calculations.
You can set the SPF delay and hold time to lower values to cause the device to change to alternate paths more quickly if a route fails.
Note that lower values for these parameters require more CPU processing time.
You can change one or both of the timers.
NOTE
If you want to change only one of the timers, for example, the SPF delay timer, you must specify the new value for this timer as
well as the current value of the SPF hold timer, which you want to retain. The device does not accept only one timer value.
NOTE
If you configure SPF timers between 0 through 100, they default to
0.
OSPFv2 LSA refreshes
To prevent a refresh from being performed each time an individual LSA's refresh timer expires, OSPFv2 LSA refreshes are delayed for a
specified time interval. This pacing interval can be altered.
The device paces OSPFv2 LSA refreshes by delaying the refreshes for a specified time interval instead of performing a refresh each time
an individual LSA’s refresh timer expires. The accumulated LSAs constitute a group, which the device refreshes and sends out together in
one or more packets.
The pacing interval, which is the interval at which the device refreshes an accumulated group of LSAs, is configurable in a range from 10
through 1800 seconds (30 minutes). The default is 240 seconds (4 minutes). Thus, every four minutes, the device refreshes the group
of accumulated LSAs and sends the group together in the same packets.
The pacing interval is inversely proportional to the number of LSAs the device is refreshing and aging. For example, if you have
approximately 10,000 LSAs, decreasing the pacing interval enhances performance. If you have a very small database (40 to 100 LSAs),
increasing the pacing interval to 10 to 20 minutes may enhance performance only slightly.
OSPFv2 LSA refreshes
Brocade FastIron Layer 3 Routing Configuration Guide
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