Interval in seconds during which routing information regarding
better paths is suppressed. A route enters into a forced holddown
state when an update packet is received that indicates the route is
unreachable and when this timer value is nonzero. After this timer
has expired, if the value is less that 120 - the route enters a
holddown state for the rest of the period until 120. During this time
advertisements for better paths are accepted if any.