D-Link DGS-3620-52T CLI Guide - Page 166

xStack® DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch CLI Reference Guide Example This command shows how to disable the comparison of the Multi Exit Discriminator (MED): DGS-3620-28SC:admin# config bgp always_compare_med disable Command: config bgp always_compare_med disable Success. DGS-3620-28SC:admin# 12-17 config bgp dampening Description The purpose of this command is to eliminate the dampening of routes and thus to avoid unstable networks caused by flapping routes. The following describes the way how it is achieved. If a prefix is removed or is added, BGP will add a penalty on the route of 1000; if an attribute of received route changes, BGP will add a penalty on the route of 500. Suppose that the half-life is configured to be 15min, the re-use value will be 800, and the suppress value will be 1500. 1. When a route flaps (from up to down), add the penalty by 1000.Since the penalty is smaller than the suppress value, BGP will work normally. It will send a withdraw message (an update message) to the neighbors. 2. The penalty of the route will decrease as time elapses. Here we assume that it pass 7.5 minutes, then the penalty of the route is 1000-500*7.5/15=750. 3. If another flap occurs (the route change from down to up) then the penalty of the route will be 1750 which is larger than the suppress value, and the route will be dampened. BGP will not send an update message for this status change. 4. When the penalty of the route decreases and become smaller than the re-use value (800), the route will not be dampened and the update message will be sent again. Note: If the dampening ability is enabled and there are one or more dampened routes, the dampened routes will be released to be the normal state immediately after we disable the dampening function. Format config bgp dampening [route_map | clear_routemap | {state [enable | disable] | half_life | reuse | suppress | max_suppress_time | un_reachability_half_life }(1)] Parameters route_map - The route_map here is to set the dampening to be criterial. - Enter the route map name here. This name can be up to 16 characters long. clear_routemap - This option will withdraw the route_map configuration. state - (Optional) Specifies the BGP dampening function's state. enable - Specifies that the BGP dampening function's state will be enabled. 161