Configuring ospf area parameters – Cisco ASA 5505 User Manual

Page 472

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24-10

Cisco ASA 5500 Series Configuration Guide using the CLI

Chapter 24 Configuring OSPF

Customizing OSPF

Configuring OSPF Area Parameters

You can configure several OSPF area parameters. These area parameters (shown in the following task
list) include setting authentication, defining stub areas, and assigning specific costs to the default
summary route. Authentication provides password-based protection against unauthorized access to an
area.

Stub areas are areas into which information on external routes is not sent. Instead, there is a default
external route generated by the ABR into the stub area for destinations outside the autonomous system.
To take advantage of the OSPF stub area support, default routing must be used in the stub area. To further
reduce the number of LSAs sent into a stub area, you can use the no-summary keyword of the area stub
command on the ABR to prevent it from sending a summary link advertisement (LSA Type 3) into the
stub area.

To specify area parameters for your network, perform the following steps:

Detailed Steps

ospf retransmit-interval

seconds

Example:

hostname(config-interface)# ospf

retransmit-interval seconds

Allows you to specify the number of seconds between LSA
retransmissions for adjacencies belonging to an OSPF interface.

The value for seconds must be greater than the expected
round-trip delay between any two routers on the attached
network. The range is from 1 to 65535 seconds. The default value
is 5 seconds.

In this example, the retransmit-interval value is set to 15.

ospf transmit-delay

seconds

Example:

hostname(config-interface)# ospf

transmit-delay 5

Sets the estimated number of seconds required to send a link-state
update packet on an OSPF interface. The seconds value ranges
from 1 to 65535 seconds. The default value is 1 second.

In this example, the transmit-delay is 5 seconds.

ospf network point-to-point non-broadcast

Example:

hostname(config-interface)# ospf network

point-to-point non-broadcast

Specifies the interface as a point-to-point, nonbroadcast network.

When you designate an interface as point-to-point, nonbroadcast,
you must manually define the OSPF neighbor; dynamic neighbor
discovery is not possible. See the

“Defining Static OSPF

Neighbors” section on page 24-12

for more information.

Additionally, you can only define one OSPF neighbor on that
interface.

Command

Purpose

Command

Purpose

Step 1

router ospf

process_id

Example:

hostname(config)# router ospf 2

Creates an OSPF routing process and enters router configuration
mode for the OSPF process that you want to redistribute.

The process_id argument is an internally used identifier for this
routing process and can be any positive integer. This ID does not
have to match the ID on any other device; it is for internal use
only. You can use a maximum of two processes.

Step 2

Do one of the following to configure optional OSPF area parameters:

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