Dell Force10 S4810P

232 | Border Gateway Protocol
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When dampening is applied to a route, its path is described by one of the following terms:
• history entry—an entry that stores information on a downed route
• dampened path—a path that is no longer advertised
• penalized path—a path that is assigned a penalty
The CLI example below shows configuring values to start reusing or restarting a route, as well as their
default values.
Figure 9-31. Setting Reuse and Restart Route Values
Use the following command in the CONFIGURATION ROUTER BGP mode to configure route flap
dampening parameters.
Command Syntax Command Mode Purpose
bgp dampening
[half-life | reuse |
suppress
max-suppress-time]
[route-map
map-name]
CONFIG-ROUTER-BGP Enable route dampening.
Enter the following optional parameters to configure route
dampening parameters:
• half-life range: 1 to 45. Number of minutes after which the
Penalty is decreased. After the router assigns a Penalty of 1024
to a route, the Penalty is decreased by half after the half-life
period expires. (Default: 15 minutes)
• reuse range: 1 to 20000. This number is compared to the
flapping route’s Penalty value. If the Penalty value is less than
the reuse value, the flapping route is once again advertised (or no
longer suppressed). Withdrawn routes are removed from history
state. (Default: 750)
• suppress range: 1 to 20000. This number is compared to the
flapping route’s Penalty value. If the Penalty value is greater than
the suppress value, the flapping route is no longer advertised
(that is, it is suppressed). (Default: 2000.)
• max-suppress-time range: 1 to 255. The maximum number of
minutes a route can be suppressed. The default is four times the
half-life value. (Default: 60 minutes.)
• route-map map-name: name of a configured route map. Only
match commands in the configured route map are supported. Use
this parameter to apply route dampening to selective routes.
FTOS(conf-router_bgp)#bgp dampening ?
<1-45> Half-life time for the penalty (default = 15)
route-map Route-map to specify criteria for dampening
<cr>
FTOS(conf-router_bgp)#bgp dampening 2 ?
<1-20000> Value to start reusing a route (default = 750)
FTOS(conf-router_bgp)#bgp dampening 2 2000 ?
<1-20000> Value to start suppressing a route (default = 2000)
FTOS(conf-router_bgp)#bgp dampening 2 2000 3000 ?
<1-255> Maximum duration to suppress a stable route (default = 60)
FTOS(conf-router_bgp)#bgp dampening 2 2000 3000 10 ?
route-map Route-map to specify criteria for dampening
<cr>
Set time before
value decrements
Set readvertise value
Set suppress value
Set time to suppress a route