IP Routing Features

Configuring OSPF

Configuring OSPF

This section describes how to configure OSPF on HP Series 5300XL Switches using the CLI interface.

To display OSPF configuration information and statistics, see “Displaying OSPF Information” on page 16-52.

Overview of OSPF

OSPF is a link-state routing protocol. The protocol uses link-state advertise­ ments (LSA) to update neighboring routers regarding its interfaces and infor­ mation on those interfaces. The Series 5300XL Switch floods these LSAs to all neighboring routers to update them regarding the interfaces. Each router maintains an identical database that describes its area topology to help a router determine the shortest path between it and any neighboring router.

HP Series 5300XL Switches support the following types of LSAs, which are described in RFC 2328:

Router link

Network link

Summary link

Autonomous system (AS) summary link

AS external link

OSPF is built upon a hierarchy of network components. The highest level of the hierarchy is the Autonomous System (AS). An autonomous system is defined as a number of networks, all of which share the same routing and administration characteristics.

An AS can be divided into multiple areas. Each area represents a collection of contiguous networks and hosts. Areas define the limit to which link-state advertisements are broadcast, thereby limiting the amount of flooding that occurs within the network. An area is represented in OSPF by either an IP address or a number.

You can further limit the broadcast area of flooding by defining an area range. The area range allows you to assign an aggregate value to a range of IP addresses. This aggregate value becomes the address that is advertised instead all of the individual addresses it represents being advertised. You can assign up to 8 ranges in an OSPF area.

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