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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter24 Configuring OSPF
Customizing OSPF
Note OSPF does not support summary-address 0.0.0.0 0.0.0.0.
Defining Static OSPF Neighbors
You need to define static OSPF neighbors to advertise OSPF routes over a point-to-point, non-broadcast
network. This feature lets you broadcast OSPF advertisements across an existing VPN connection
without having to encapsulate the advertisements in a GRE tunnel.
Before you begin, you must create a static route to the OSPF neighbor. See Chapter22, “Configuring
Static and Default Routes,” for more information about creating static routes.
To define a static OSPF neighbor, perform the following steps:
Detailed Steps
area area-id nssa [no-redistribution]
[default-information-originate]
Example:
hostname(config-router)# area 0 nssa
Defines an NSSA area.
summary-address ip_address mask
[not-advertise] [tag tag]
Example:
hostname(config)# router ospf 1
hostname(config-router)# summary-address
10.1.0.0 255.255.0.0
Sets the summary address and helps reduce the size of the routing
table. Using this command for OSPF causes an OSPF ASBR to
advertise one external route as an aggregate for all redistributed
routes that are covered by the address.
In this example, the summary address 10.1.0.0 includes addresses
10.1.1.0, 10.1.2.0, 10.1.3.0, and so on. Only the 10.1.0.0 address
is advertised in an external link-state advertisement.
Command Purpose
Command Purpose
Step1 router ospf process_id
Example:
hostname(config)# router ospf 2
Creates an OSPF routing process and enters router configuration
mode for this OSPF process.
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.
Step2 neighbor addr [interface if_name]
Example:
hostname(config-router)# neighbor
255.255.0.0 [interface my_interface]
Defines the OSPF neighborhood.
The addr argument is the IP address of the OSPF neighbor. The
if_name argument is the interface used to communicate with the
neighbor. If the OSPF neighbor is not on the same network as any
of the directly connected interfaces, you must specify the
interface.