Alcatel-Lucent 7705 - Damping; Figure 17 Next Entry Logic Example

Route Policies
7705 SAR OS Router Configuration Guide 431
Figure 17: Next Entry Logic Example
Damping
Damping initiates controls when routes flap. Route flapping can occur when an advertised
route between nodes alternates (flaps) back and forth between two paths due to network
problems that cause intermittent route failures. To limit processing requirements, the amount
of routing state change updates propagated must be reduced. Thus, when a route flaps beyond
a configured value (the suppress value), then that route is removed from the routing table and
routing protocols until the value falls below the reuse value.
A route can be suppressed according to the Figure of Merit (FoM) value. The FoM is a value
that is added to a route each time it flaps. A new route begins with an FoM value of 0.
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Entry 10
Match Criteria
Policy Statement
POL1
Entry 30
Match Criteria
Entry 10
Match Criteria
Policy Statement
POL2
Entry 20
Match Criteria
Entry 30
Match Criteria
Entry 10
Match Criteria
Policy Statement
POL3
Entry 20
Match Criteria
Entry 30
Match Criteria
Entry nn
Match Criteria
Entry nn
Match Criteria
Entry nn
Match Criteria
Action:
next-policy
METRIC:
nn
Action:
next-policy
Community:
Y- Z
Action:
next-policy
Local-Pref:
nn
Action:
next-policy
METRIC:300
Action:
next-policy
METRIC:200
Action:
next-policy
METRIC:100
Action:
next-policy
Community:
A:B
Action:
next-policy
Community:
C:D
Action:
next-policy
Community:
E:F
Entry 20
Match Criteria
Action:
next-policy
Local-Pref:
100
Action:
next-policy
Local-Pref:
200
Action:
next-policy
Local-Pref:
300