30-32
Catalyst 3560 Switch Software Configuration Guide
78-16156-01
Chapter 30 Configuring IP Unicast Routing
Configuring OSPF
Use the no form of these commands to remove the configured parameter value or return to the
default value.
Configuring OSPF Area Parameters
You can optionally configure several OSPF area parameters. These parameters include authentication for
password-based protection against unauthorized access to an area, stub areas, and not-so-stubby-areas
(NSSAs). Stub areas are areas into which information on external routes is not sent. Instead, the area
border router (ABR) generates a default external route into the stub area for destinations outside the
autonomous system (AS). An NSSA does not flood all LSAs from the core into the area, but can import
AS external routes within the area by redistribution.
Route summarization is the consolidation of advertised addresses into a single summary route to be
advertised by other areas. If network numbers are contiguous, you can use the area range router
configuration command to configure the ABR to advertise a summary route that covers all networks in
the range.
Note
The OSPF area router configuration commands are all optional.
Beginning in privileged EXEC mode, follow these steps to configure area parameters:
Step 8
ip ospf dead-interval seconds
(Optional) Set the number of seconds after the last device hello
packet was seen before its neighbors declare the OSPF router to be
down. The value must be the same for all nodes on a network. The
range is 1 to 65535 seconds. The default is 4 times the hello interval.
Step 9
ip ospf authentication-key key
(Optional) Assign a password to be used by neighboring OSPF
routers. The password can be any string of keyboard-entered
characters up to 8 bytes in length. All neighboring routers on the
same network must have the same password to exchange OSPF
information.
Step 10
ip ospf message digest-key keyid md5 key
(Optional) Enable MDS authentication.
•
keyid—An identifier from 1 to 255.
•
key—An alphanumeric password of up to 16 bytes.
Step 11
ip ospf database-filter all out
(Optional) Block flooding of OSPF LSA packets to the interface. By
default, OSPF floods new LSAs over all interfaces in the same area,
except the interface on which the LSA arrives.
Step 12
end
Return to privileged EXEC mode.
Step 13
show ip ospf interface [interface-name]
Display OSPF-related interface information.
Step 14
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
router ospf process-id
Enable OSPF routing, and enter router configuration mode.
