Dynamic OSPF activation and configuration
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.
NOTE:
OSPF is automatically enabled without a system reset.
General configuration steps for OSPF
To begin using OSPF on the routing switch:
Procedure
1.
In the global config context, use
ip routing
on page 197.)
2.
Execute
router ospf
to place the routing switch in the
ospf
context and to enable OSPF routing (page
A-21.)
3.
Change theOSPF RFC 1583 compliance, if needed. (See
Changing the RFC 1583 OSPF compliance
on page 198.)
4.
Use
area
to assign the areas to which the routing switch will be attached (page A-25.)
5.
Assign interfaces to the configured areas per-VLAN or per-subnet by moving to each VLAN context and
using one of the following commands:
a.
ip ospf area ospf-area-id
assigns 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.
b.
ip ospf ip-address area ospf-area-id
assigns an individual subnet to the specified area.
6.
Optional: Assign loopback interfaces to OSPF areas by using the
ip ospf area
command at the loopback
interface configuration level. (See
Assigning loopback addresses to an area
on page 203.)
7.
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.
a.
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.
b.
Enable redistribution.
Configuring external route redistribution in an OSPF domain (optional)
on page 205.
8.
Optional: Configure ranges on ABRs to reduce inter-area route advertising.
9.
Optional: Use administrative distance to influence route choices.
10.
Optional: Change OSPF trap generation.
11.
Optional: Reconfigure default parameters in the interface context, if needed. Includes
cost
,
dead-
interval
,
hello-interval
,
priority
, and others.
Chapter 11 Open Shortest Path First Protocol (OSPF)
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