OSPF Flooding Reduction

Feature History for OSPF Flooding Reduction

This table provides release and platform support information for the features explained in this module.

These features are available in all the releases subsequent to the one they were introduced in, unless noted otherwise.

Release

Feature Name and Description

Supported Platform

Cisco IOS XE 17.18.1

OSPF Flooding Reduction: OSPF Flooding Reduction is a network optimization feature that minimizes unnecessary OSPF LSA refreshes and network flooding, especially for LSAs that are stable and unchanged.

Cisco C9350 Series Smart Switches

Cisco C9610 Series Smart Switches

OSPF Flooding Reduction

The OSPF Flooding Reduction is a network optimization feature that minimizes unnecessary OSPF Link-State Advertisement (LSA) refreshes and network flooding, especially for LSAs that are stable and unchanged.

How OSPF Flooding Reduction works

OSPF devices periodically refresh LSAs to prevent them from aging out (default every 30 minutes). With flooding reduction enabled, devices set the DoNotAge (DNA) bit in their LSAs. LSAs marked with the DNA bit do not age out, so they are not periodically refreshed or flooded. This reduces control-plane overhead and conserves bandwidth, especially in stable networks with few topology changes.

Configure OSPF Flooding Reduction

Perform this task on each interface you want to configure OSPF flooding reduction.

Procedure

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password, if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

interface type number

Example:

Device(config)# interface ethernet 1/0/1

Configures an interface.

Step 4

ip ospf flood-reduction

Example:

Device(config-if)# ip ospf flood-reduction

Reduces unnecessary flooding and refreshing of LSAs in stable networks.

Step 5

end

Example:

Device(config-if)# end

Returns to privileged EXEC mode.

Configuration example for OSPF Flooding Reduction

This example shows how to configure OSPF Flooding Reduction.

Device> enable
Device# configure terminal
Device(config)# interface ethernet 1/0/1
Device(config-if)# ip ospf flood-reduction
Device(config-if)# end