Lectures notes for 2010 - KTH

Triggered updates and Hold-Downs
To decrease convergence time - when the topology changes send out an update
immediately.
However, if a node can learn about connectivity from more than one source, then
if a delete happens before the add, then the existence of the route is asserted;
therefore the hold-down rules says:
When a route is removed, no update of this route is accepted for
some period of time - to give everyone a chance to remove the route.
This period of time is the Hold-down time.
The result is to decrease the rate of convergence; but the combined effect of
triggered updates + hold-downs leads to faster convergence than not using
triggered updates.
Maguire Triggered updates and Hold-Downs 7: 18 of 70
maguire@kth.se 2010.03.21 Internetworking/Internetteknik