| Device Online Help |
|
While aggregating or injecting routes to other routers, a router may not have a route to the aggregated destination, which causes a "black hole." To avoid routing loops, you can configure a black hole static-route to the destination it is advertising.
A black hole route is a route with invalid next hop, so that the data packets destined to this network will be dropped by the switch.
When you specify a route preference, be sure that you configure the preference value appropriately so that when the black-hole route is used, it gets elected as the best route. Before adding the black hole route a check is made to ensure that no other static route to that identical destination in an enabled state exists. If such a route exists, then you are not allowed to add the black hole route, and an error message is generated.
However, if there is an enabled black hole route, then you will not be allowed to add another static route to that destination. You are required to first delete or disable the black hole route in order to add a regular static route to that destination.
|
|