prefix-update-rate

Sets the rate at which prefix update requests are taken out of the queue by CNA.

prefix-update-rate <rate> [ <priority_rate> ] <unit>
 
no prefix-update-rate
 

• rate--representing number of updates; range depends upon unit
• per-second: 0 through 100
• per-minute: 0 through 6000
• per-hour: 0 through 360000
• per-day: 0 through 8640000
• priority_rate--representing number of priority-prefix updates. It must be equal to or greater than rate. If you choose not to set this value, it will be set to rate; range: same as rate
• unit--interval; can be one of the following strings:
• per-second
• per-minute
• per-hour
• per-day

Must be in engine configuration mode (config-engine), which requires privileged-level access.

rate--10 per second

priority_rate--same as rate, if you do not set this value

unit--per-second

Whenever CNA determines that it is necessary to assert a change in routes, it places an update request into a queue. (Changes in response to critical conditions--loss of coverage for a particular prefix, or link failure--bypass this queue and are dealt with immediately.)

The update rate determines how fast update requests are processed out of the queue.

The priority rate determines how fast updates for priority prefixes are processed. See the priority-prefix command.

In general, the faster the rate of updates the faster the system can react to general performance deteriorations. The actual rate should be based on your network’s traffic patterns, link bandwidths, and number of prefixes. The more resources your network has, the faster you can set the rate.

However, rates should not be faster than 50 per-second.

Setting the rate to 0 causes CNA to stop asserting routes, an alternative to using the route-assert-mode command to shift temporarily to reporting mode (which has the side effect of clearing the CNA prefix database and measurement counters). You should not rely on a rate of 0 for long-term suspension of route assertions, since it will prevent CNA from responding to brownout or blackout conditions.

With an update rate of 0, no decisions will be allowed out of the decision-maker’s queue, thereby preventing assertions; however, route withdrawals may still occur, if, for example, assert-routes-matching-bgp behavior is disabled or all natural BGP links are in the winner set.

The no form of the prefix-update-rate command resets update rates to their defaults.