Administrator's Guide v4.1.1 Manual

• OSPF can be configured on either a point-to-point or broadcast network.
• OSPF can be enabled on the following interfaces: gigabitethernet, tengigabitethernet,
fortygigabitethernet, loopback, and ve.
• On enabling OSPF over a loopback interface, the network is advertised as a stub network in the
router LSA for the attached area. OSPF control packets, such as hellos , are not transmitted on
loopback interfaces and adjacencies will not form.
Configuring OSPF
Consider the topics discussed below when configuring OSPF.
Performing basic OSPF configuration
This section addresses the basics of OSPF configuration.
Enabling OSPF
To begin using OSPF on the router, perform these steps:
1. Follow the rules below.
• If a router is to operate as an ASBR, you must enable the ASBR capability at the system level.
• Redistribution must be enabled on routers configured to operate as ASBRs.
• All router ports must be assigned to one of the defined areas on an OSPF router. When a port is
assigned to an area, all corresponding subnets on that port are automatically included in the
assignment.
2. Enter the router ospf command in RBridge ID configuration mode to enable OSPF on the router.
This is shown in OSPF over VRF on page 589.
3. Assign the areas to which the router will be attached. Refer to Area types on page 586.
4. Assign individual interfaces to the OSPF areas. Refer to Assigning interfaces to an area on page
593.
5. Assign a virtual link to any ABR that does not have a direct link to the OSPF backbone area. Refer to
Virtual links on page 588.
6. Refer to Changing default settings on page 595.
Setting up the backbone area
To set up the backbone area shown in Autonomous System on page 583, do the following:
1. In privileged EXEC mode on Router A, issue the configure command to enter global configuration
mode.
2. Enter the interface vlan command followed by the VLAN number to create a VLAN.
3. Enter the rbridge-id command followed by the RBridge ID to enter RBridge configuration mode.
4. Enter the interface ve command followed by the VLAN number to enter interface configuration
mode.
5. Enter the ip address operand followed by the IP address/subnet for the interface.
6. Issue the ip ospf area operand followed by the area ID to assign the interface to this area.
Configuring OSPF
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