OSPF Per-Interface Link-Local Signaling

Enable or disable link-local signaling on a per interface basis

Perform this procedure to enable or disable link-local signaling on a per-interface basis.

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 interface-id

Example:

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

Enters interface configuration mode, and specifies the Layer 3 interface to configure.

Step 4

ip address ip-address [mask] [secondary]

Example:

Device(config-if)# ip address 10.2.145.20 255.255.255.0

Sets a primary or secondary IP address for an interface.

  • ip-address : The IPv4 address you want to assign to the interface.

  • mask : The subnet mask for the IP address.

  • secondary : (Optional) Specifies that the address is a secondary IP address, allowing the interface to have multiple IP addresses from different subnets.

Step 5

no ip directed-broadcast[access-list-number | extended access-list-number]

Example:

Device(config-if)# no ip directed-broadcast

Drops directed broadcasts destined for the subnet to which that interface is attached, rather than broadcasting them.

access-list-number | extended-access-list-number : (Optional) Allows you to specify an access list to filter which directed broadcasts are affected.

Step 6

ip ospf message-digest-key key-id encryption-type md5 key

Example:

Device(config-if)# ip ospf message-digest-key 100 md5 testing

Enables OSPF Message Digest 5 (MD5) algorithm authentication.

  • key-id : A unique identifier (number) for the key on this interface. The range is from 1 to 255.

  • encryption-type: The type of encryption

    • 0 means the password is in plain text.

    • 7 means the password is encrypted in Cisco’s type 7 encryption.

  • md5 : Specifies that MD5 authentication is being used.

  • key : The actual key string (password) used for authentication.

Step 7

[no | default] ip ospf lls [disable]

Example:

Device(config-if)# ip ospf lls disable

Enables or disables link-local signaling on an interface, regardless of the global setting.

  • ip ospf lls : Enables OSPF link-local signaling on the interface (overrides global settings if configured).

  • disable : Disables link-local signaling on this specific interface, even if link-local signaling is enabled globally.

  • no : Removes the ip ospf lls configuration or disables link-local signaling on the interface.

  • default : Resets the command to its default state on the interface.

Step 8

end

Example:

Device(config-if)# end

Returns to privileged EXEC mode.