Motorola BSR 2000, Configuration And Management Manual

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Release 1.0 Configuring Routing Policy
526360-001-00 Rev. B MGBI 8-13
For detailed information on the redistribute command, refer to the
BSR 2000
Command Reference Guide
.
Example
This example redistributes routes learned from OSPF into BGP. The commands
enable BGP, specify the autonomous system 100, and specify OSPF as the protocol
type for the redistribution.
router bgp 100
redistribute ospf route-map "new york"
Applying a Damping Criteria
Route flapping
occurs when a link constantly fluctuates between being available and
unavailable. Every time a link changes its availability, the upstream neighbor sends an
update message to all its neighbors. These routes are advertised globally. This process
continues until the underlying problem is fixed.
Route flap damping
minimizes instability caused by route flapping. Use policy-based
route flap damping to apply the following damping criteria to specific routes:
■
half-life
—half-life period in minutes in the range 1 - 45. The default is 10. When
a BGP route has been assigned a penalty, the penalty is decreased by a half after
each half-life period (which is 15 minutes by default). Each time a route flaps, the
router configured for route flap damping assigns the route a penalty. Penalties are
cumulative. BGP stores the penalty for all reachable and unreachable routes that
have experienced recent flaps.
■
reuse
— reuse limit in the range 1 - 20000. The default is 750. As the penalty for
a flapping route decreases and falls below this reuse limit, the route is
unsuppressed. The route is added back to the BGP route table and used for
forwarding. The process of unsuppressing routers occurs in 10-second
increments. Every 10 seconds the router determines which routes are
unsuppressed and advertises them globally.
■
suppress
— the suppress limit in the range 1 - 20000. The default is 2000. A route
is suppressed when its penalty exceeds this limit.
■
max-suppress-time
— the maximum suppression time in minutes in the range 1 -
255. The default is four times the half-life. This value is the maximum amount of
time a route can be suppressed.