Basic OSPF configuration

Configuring OSPF

This section explains how to enable and restart the OSPF process on your system. After enabling see the section, to learn how to customize the OSPF process on your system.

•Enabling OSPF

•Restarting the OSPF Process

Enabling OSPF

To enable OSPF, you need to create an OSPF routing process, specify the range of IP addresses associated with the routing process, then assign area IDs associated with that range of IP addresses.

To enable OSPF, perform the following detailed steps:

Detailed Steps

	Command	Purpose
Step 1	router ospf process_id Example: hostname(config)# router ospf 2	This creates an OSPF routing process, and the user enters router configuration mode for this OSPF process. The process_id is an internally used identifier for this routing process. It 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	network ip_address mask area area_id Example: hostname(config)# router ospf 2 hostname(config-router)# network 10.0.0.0 255.0.0.0 area 0	This step defines the IP addresses on which OSPF runs and to define the area ID for that interface.

Restarting the OSPF Process

This step allows you to remove the entire OSPF configuration you have enabled. Once this is cleared, you must reconfigure OSPF again using the router ospf command, perform the following step:

Command	Purpose
clear ospf pid {process | redistribution |  counters [neighbor [neighbor-interface] [neighbor-id]]} Example: hostname(config)# clear ospf	This remove entire OSPF configuration you have enabled. Once this is cleared, you must reconfigure OSPF again using the router ospf command.

Customizing OSPF

This section explains how to customize the OSPF process and includes the following topics:

•Redistributing Routes Into OSPF

•Generating a Default Route

•Configuring OSPF Interface Parameters

•Configuring Route Summarization Between OSPF Areas

•Configuring OSPF Interface Parameters

•Configuring OSPF Area Parameters

•Configuring OSPF NSSA

•Configuring Route Calculation Timers

•Defining Static OSPF Neighbors

•Logging Neighbors Going Up or Down

Redistributing Routes Into OSPF

The ASA can control the redistribution of routes between OSPF routing processes. The ASA matches and changes routes according to settings in the redistribute command or by using a route map.

If you want to redistribute a route by defining which of the routes from the specified routing protocol are allowed to be redistributed into the target routing process, you must firstgenerate a default map and then define a route map.

To redistribute static, connected, RIP, or OSPF routes into an OSPF process, perform the following steps:

Detailed Steps

	Command	Purpose
Step 1	router ospf process_id Example: hostname(config)# router ospf 2	This creates an OSPF routing process, and the user enters router configuration mode for tfor the OSPF process you want to redistribute. The process_id is an internally used identifier for this routing process. It 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 redistribute the selected route type into the OSPF routing process:
	redistribute connected  [metric metric-value]  metric-type {type-1 | type-2}]  tag tag_value] [subnets] [route-map map_name] Example: hostname(config)# redistribute connected	This step redistributes connected routes into the OSPF routing process
	redistribute static [metric metric-value] [metric-type {type-1 | type-2}] [tag tag_value] [subnets] [route-map map_name Example: hostname(config)# redistribute static	This step redistribute static routes into the OSPF routing process.
	redistribute ospf pid [match {internal | external [1 | 2] | nssa-external [1 | 2]}] [metric metric-value] [metric-type {type-1 | type-2}] [tag tag_value] [subnets] [route-map map_name] Example: hostname(config)# route-map 1-to-2 permit hostname(config-route-map)# match metric 1 hostname(config-route-map)# set metric 5 hostname(config-route-map)# set metric-type type-1 hostname(config-route-map)# router ospf 2 hostname(config-router)# redistribute ospf  1 route-map 1-to-2	This step allows you to redistribute routes from an OSPF routing process into another OSPF routing process. You can either use the match options in this command to match and set route properties, or you can use a route map. The subnet option does not have equivalents in the route-map command. If you use both a route map and match options in theredistribute command, then they must match. This example shows route redistribution from OSPF process 1 into OSPF process 2 by matching routes with a metric equal to 1. The ASA redistributes these routes as external LSAs with a metric of 5, metric type of Type 1.
	redistribute rip [metric metric-value] [metric-type {type-1 | type-2}] [tag tag_value] [subnets] [route-map map_name] Example: hostname(config)# redistribute rip 25	This step allows you to redistribute routes from a RIP routing process into the OSPF routing process.
	redistribute eigrp as-num [metric metric-value] [metric-type {type-1 | type-2}] [tag tag_value] [subnets] [route-map map_name] Example: hostname(config)# redistribute eigrp 2	This step allows you to redistribute routes from an EIGRP routing process into the OSPF routing process.