Brocade Communications Systems ICX 7250 series, Руководство по настройке

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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 from 0 through 100, they default to
0.
OSPFv3 administrative distance
Devices can learn about networks from various protocols and select a route based on the source of the route information. This decision
can be influenced if the default administrative distance for OSPFv3 routes is changed. Consequently, the routes to a network may differ
depending on the protocol from which the routes were learned.
You can influence the device’s decision by changing the default administrative distance for OSPFv3 routes. You can configure a unique
administrative distance for each type of OSPFv3 route. For example, you can configure the Brocade device to prefer a static route over
an OSPFv3 inter-area route and to prefer OSPFv3 intra-area routes over static routes. The distance you specify influences the choice of
routes when the device has multiple routes to the same network from different protocols. The device prefers the route with the lower
administrative distance.
You can specify unique default administrative distances for the following OSPFv3 route types:
• Intra-area routes
• Inter-area routes
• External routes
NOTE
The choice of routes within OSPFv3 is not influenced. For example, an OSPFv3 intra-area route is always preferred over an
OSPFv3 inter-area route, even if the intra-area route’s distance is greater than the inter-area route’s distance.
OSPFv3 LSA refreshes
To prevent a refresh from being performed each time an individual LSA's refresh timer expires, OSPFv3 LSA refreshes are delayed for a
specified time interval. This pacing interval can be altered.
The device paces OSPFv3 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.
OSPFv3 administrative distance
Brocade FastIron Layer 3 Routing Configuration Guide
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