Configuring a Switch to Filter LSAs to Be Sent

Context

When multiple links exist between two switches, you can configure the local switch to filter the LSAs to be sent over certain links. This prevents unnecessary retransmission of LSAs and saves bandwidth resources.

Perform the following steps on a switch running OSPF.

Procedure

Run system-view

The system view is displayed.
Run interface interface-type interface-number

The interface view is displayed.
(Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.

By default, an Ethernet interface works in Layer 2 mode.

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
Run ospf filter-lsa-out { all | { summary [ acl { acl-number | acl-name } ] | ase [ acl { acl-number | acl-name } ] | nssa [ acl { acl-number | acl-name } ] } ^* }

The switch is configured to filter the LSAs to be sent.

By default, a switch does not filter the LSAs to be sent.