OSPF automatically activates when enabled with router ospf. All configuration commands affecting OSPF (except reconfiguring the router ID) are dynamically implemented and can be used without restarting OSPF routing. (To reconfigure the router ID, see Changing the router ID".)
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NOTE: OSPF is automatically enabled without a system reset. |
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To begin using OSPF on the routing switch:
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In the global config context, use
ip routingto enable routing (page Enabling IP routing.) -
Execute
router ospfto place the routing switch in theospfcontext and to enable OSPF routing (page A-21.) -
Change theOSPF RFC 1583 compliance, if needed. (See Changing the RFC 1583 OSPF compliance setting.)
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Use
areato assign the areas to which the routing switch will be attached (page A-25.) -
Assign interfaces to the configured areas per-VLAN or per-subnet by moving to each VLAN context and using one of the following commands:
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ip ospf area ospf-area-idassigns all interfaces in the VLAN to the same area. Use this option when there is only one IP address configured on the VLAN or you want all subnets in the VLAN to belong to the same OSPF area. -
ip ospf ip-address area ospf-area-idassigns an individual subnet to the specified area.
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Optional: Assign loopback interfaces to OSPF areas by using the
ip ospf areacommand at the loopback interface configuration level. (See Assigning loopback addresses to an area.) -
Optional: On each routing switch used as an ASBR in your OSPF domain, configure redistribution to enable importing the routes you want to make available in the domain.
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On an ASBR in a backbone, normal, or NSSA area where you want to import external routes, configure redistribution filters to define the external routes you do not want imported.
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See Configuring external route redistribution in an OSPF domain (optional).
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Optional: Configure ranges on ABRs to reduce inter-area route advertising.
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Optional: Use administrative distance to influence route choices.
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Optional: Reconfigure default parameters in the interface context, if needed. Includes
cost,dead-interval,hello-interval,priority, and others. -
Configure virtual links for any areas not directly connected to the backbone.
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If the switch is to operate as an ASBR, you must enable redistribution (step Step 7. When you do that, ASBR capability is automatically enabled. For this reason, you should first configure redistribution filters on the ASBR. Otherwise, all possible external routes will be allowed to flood the domain. (See Configuring external route redistribution in an OSPF domain (optional).)
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Each VLAN interface on which you want OSPF to run must be assigned to one of the defined areas. When a VLAN interface is assigned to an area, the IP address is automatically included in the assignment. To include additional addresses, you must enable OSPF on them separately, or use the "all" option in the assignment.
When first enabling OSPF, you may want to consider configuring ranges and restricting redistribution (if an ASBR is used) to avoid unwanted advertisements of external routes. You may also want to enable the OSPF trap and authentication features to enhance troubleshooting and security. However, Hewlett Packard Enterprise generally recommends that the remaining parameters with non-null default settings be left as-is until you have the opportunity to assess OSPF operation and determine whether any adjustments to non-default settings is warranted.