Affected Components; Route Types; Supported Protocols; How To Configure Ip Event Dampening - Cisco Nexus 3548 Configuration Manual

Configuring IP Event Dampening

Affected Components

When an interface is not configured with dampening, or when an interface is configured with dampening but
is not suppressed, the routing protocol behavior as a result of interface state transitions is not changed by the
IP Event Dampening feature. However, if an interface is suppressed, the routing protocols and routing tables
are immune to any further state transitions of the interface until it is unsuppressed.

Route Types

The following interfaces are affected by the configuration of this feature:
• Connected routes:
• Static routes:
Note Only the primary interface can be configured with this feature, and all subinterfaces are subject to the same
dampening configuration as the primary interface. IP Event Dampening does not track the flapping of individual
subinterfaces on an interface.

Supported Protocols

All the protocols that are used are impacted by the IP Event Dampening feature. The IP Event Dampening
feature supports Border Gateway Protocol (BGP), Enhanced Interior Gateway Routing Protocol (EIGRP),
Hot Standby Routing Protocol (HSRP), Open Shortest Path First (OSPF), Routing Information Protocol (RIP),
and VRRP. Ping and SSH to the concerned interface IP address does not work.
Note
The IP Event Dampening feature has no effect on any routing protocols if it is not enabled or an interface is
not dampened.

How to Configure IP Event Dampening

Enabling IP Event Dampening

The dampening command is entered in interface configuration mode to enable the IP Event Dampening
feature. If this command is applied to an interface that already has dampening configured, all dampening
states are reset and the accumulated penalty will be set to 0. If the interface has been dampened, the accumulated
penalty will fall into the reuse threshold range, and the dampened interface will be made available to the
network. The flap counts, however, are retained.
• The connected routes of dampened interfaces are not installed into the routing table.
• When a dampened interface is unsuppressed, the connected routes will be installed into the routing
table if the interface is up.
• Static routes assigned to a dampened interface are not installed into the routing table.
• When a dampened interface is unsuppressed, the static route will be installed into the routing table
if the interface is up.
Cisco Nexus 3548 Switch NX-OS Interfaces Configuration Guide, Release 9x
Affected Components
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