Alcatel-Lucent 7750 SR-OS, Configuration Manual

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Page 386 7750 SR OS Router Configuration Guide
Multiple unique (different prefix/mask-length ) route-unknown event nodes can be configured within
the priority-event node up to the maximum limit of 32 events.
The route-unknown command can reference any valid IP addres mask-length pair. The IP address
and associated mask length define a unique IP router prefix. The dynamic monitoring of the route
prefix results in one of the following event operational states:
An existing route prefix in the RTM must be active (used by the IP forwarding engine) to clear the
event operational state. It may be less specific (the defined prefix may be contained in a larger prefix
according to Classless Inter-Domain Routing (CIDR) techniques) if the event has the
less-specific
statement defined. The less specific route that incorporates the router prefix may be the default route
(0.0.0.0) if the
less-specific allow-default statement is defined. The matching prefix may be required
to have a specific next hop IP address if defined by the event next-hop command. Finally, the source
of the RTM prefix may be required to be one of the dynamic routing protocols or be statically defined
if defined by the event
protocol command. If an RTM prefix is not found that matches all the above
criteria (if defined in the event control commands), the event is considered to be set. If a matching
prefix is found in the RTM, the event is considered to be cleared.
When an event transitions from clear to set, the set is processed ediately and must be reflected in the
associated virtual router instances in-use priority value. As the event transitions from clear to set, a
hold set timer is loaded with the value configured by the events
hold-set command. This timer
prevents the event from clearing until it expires, damping the effect of event flapping. If the event
clears and becomes set again before the hold set timer expires, the timer is reset to the
hold-set value,
extending the time before another clear can take effect.
The no form of the command is used to remove the specific prefix/mask-length monitoring event.
The event can be removed at anytime. When the event is removed, the in-use priority of all associated
route-unknown
Operational State
Description
Set – non-existent The route does not exist in the route table.
Set – inactive The route exists in the route table but is not being used.
Set – wrong next hop The route exists in the route table but does not meet the next-hop
requirements.
Set – wrong protocol The route exists in the route table but does not meet the protocol
requirements.
Set – less specific
found The route exists in the route table but does is not an exact match and
does not meet any
less-specific requirements.
Set – default best
match The route exists in the route table as the default route but the default
route is not allowed for route matching.
Cleared – less specific
found A less specific route exists in the route table and meets all criteria
including the
less-specific requirements.
Cleared – found The route exists in the route table manager and meets all criteria.