OSPF

This help contains the following topics:

·     Introduction

¡     OSPF instances

¡     OSPF areas

¡     OSPF neighbors

·     Configure OSPF

¡     Configure an OSPF instance

¡     Configure an OSPFv2 area

¡     Configure an OSPFv3 area

Introduction

Open Shortest Path First (OSPF) is a link-state IGP that encapsulates its data directly in IP packets using protocol number 89.

OSPF version 2 and OSPF version 3 are supported. OSPF version 2 is used for IPv4. OSPF version 3 is used for IPv6.

OSPF instances

To enable OSPF, you must first create an OSPF instance, specify the area associated with the instance, and specify network segments and interfaces for the area. An interface attached to a network of an area will run OSPF in the area. OSPF will advertise the direct route of the interface.

OSPF supports multiple instances. You can enable multiple OSPF instances on a device by specifying different names for the OSPF instances. OSPF instance names are locally meaningful. Two devices can exchange packets with each other even if their instance names are different.

OSPF areas

OSPF splits an AS into multiple areas. Each area is identified by an area ID. The boundaries between areas are devices rather than links. A device can belong to different areas, but a network segment (or a link) can only reside in one area. You must specify an area for each OSPF interface. You can configure route summarization on ABRs to reduce the number of LSAs advertised to other areas and minimize the effect of topology changes.

OSPF neighbors

In an OSPF network, two devices can exchange link state information only after they establish a neighbor relationship. Upon receiving a hello packet from an OSPF interface, the device checks parameters in the packet, including router ID, area ID, authentication information, subnet mask, and hello interval. If the parameters match its own, the receiving device considers the sending device an OSPF neighbor.

Configure OSPF

Configure an OSPF instance

1.     Click the Network tab.

2.     In the navigation pane, select Routing > OSPF.

3.     Click the OSPF Instance tab.

4.     Click Create.

5.     Configure the OSPF instance parameters.

Table 1 OSPF instance configuration items

6.     Click OK.

The OSPF instance will be displayed on the OSPF instance page.

Configure an OSPFv2 area

1.     Click the Network tab.

2.     In the navigation pane, select Routing > OSPF.

3.     Click the OSPF Instance tab.

4.     Click the number in the Number of OSPF areas column of an OSPFv2 instance.

5.     Click Create.

6.     Configure the OSPFv2 area parameters.

Table 2 OSPFv2 area configuration items

7.     Click OK.

The OSPFv2 area will be displayed on the OSPFv2 area page.

8.     Click the OSPF Instance tab, and then click the number in the Number of redistributed routes column of an OSPFv2 instance.

9.     Click Create.

10.     Configure the OSPFv2 redistributed route parameters.

Table 3 OSPFv2 redistributed route configuration items

11.     Click OK.

Configure an OSPFv3 area

1.     Click the Network tab.

2.     In the navigation pane, select Routing > OSPF.

3.     Click the OSPF Instance tab.

4.     Click the number in the Number of OSPF areas column of an OSPFv3 instance.

5.     Click Create.

6.     Configure the OSPFv3 area parameters.

Table 4 OSPFv3 area configuration items

7.     Click OK.

The OSPFv3 area will be displayed on the OSPFv3 area page.

8.     Click the OSPF Instance tab, and then click the number in the Number of OSPF interfaces column of the OSPFv3 instance.

9.     Click Create.

10.     Configure the OSPFv3 interface parameters.

Table 5 OSPFv3 interface configuration items

11.     Click OK.

The interface will be displayed on the OSPFv3 interface page.