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Enables and disables require behavior, which determines whether CNA will assert a route before hearing about the prefix from all edge routers.
require-routes-from-all-routers no require-routes-from-all-routers
Must be in engine configuration mode (config-engine), which requires privileged-level access.
When require behavior is enabled, CNA will not assert a route until all of its BGP peers have reported routes to the prefix. This behavior prevents CNA from being the source of routing information previously unknown to the router.
In the following example, there are two links on each of two routers: 1/1, 1/2, 2/1 and 2/2.
Figure 1: Asserting routes with multiple routers
Router 1 has received the minimum required number of measurements for prefix 1.2.3.4/24 across both Link1/1 (the BGP selected route to the prefix, labeled “b”) and Link 1/2, and CNA has determined that Link 1/2 is the performance-route winner (labeled “w”).
If you have disabled require behavior, CNA will assert Link 1/2 as the winner route to prefix 1.2.3.4/24 to both routers, even though Router 2 has reported that it knows only about prefix 1.2.3.4/16.
With require behavior enabled (the default behavior), CNA will not assert any route to prefix 1.2.3.4/24 until Edge Router 2 has sent notice that it knows about the prefix. This will result in Edge Router 1 continuing to use Link 1/1, the BGP selected route, to prefix 1.2.3.4/24, even though CNA has determined that Link 1/2 is the better one.
Use the no form of the require-routes-from-all-routers command to disable this behavior.
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