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Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
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Chapter 38 Configuring IP Unicast Routing
Configuring OSPF
After a stack master change, the new master sends an OSPF NSF signal to neighboring NSF-aware
devices. A device recognizes this signal to mean that it should not reset the neighbor relationship with
the stack. As the NSF-capable stack master receives signals from other routes on the network, it begins
to rebuild its neighbor list.
When the neighbor relationships are reestablished, the NSF-capable stack master resynchronizes its
database with its NSF-aware neighbors, and routing information is exchanged between the OSPF
neighbors. The new stack master uses this routing information to remove stale routes, to update the
routing information database (RIB), and to update the forwarding information base (FIB) with the new
information. The OSPF protocols then fully converge.
Note
OSPF NSF requires that all neighbor networking devices be NSF-aware. If an NSF-capable router
discovers non-NSF aware neighbors on a network segment, it disables NSF capabilities for that segment.
Other network segments where all devices are NSF-aware or NSF-capable continue to provide NSF
capabilities.
Use the nsf OSPF routing configuration command to enable OSPF NSF routing. Use the show ip ospf
privileged EXEC command to verify that it is enabled.
For more information about this feature, see the Cisco Nonstop Forwarding Feature Overview at this
URL:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00800ab7fc.
html
Note
NSF is not supported on interfaces configured for Hot Standby Router Protocol (HSRP).
Configuring Basic OSPF Parameters
Enabling OSPF requires that you create an OSPF routing process, specify the range of IP addresses to
be associated with the routing process, and assign area IDs to be associated with that range.
Beginning in privileged EXEC mode, follow these steps to enable OSPF:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
router ospf process-id
Enable OSPF routing, and enter router configuration mode. The
process ID is an internally used identification parameter that is
locally assigned and can be any positive integer. Each OSPF
routing process has a unique value.
Step 3
nsf
(Optional) Enable NSF operations for OSPF.
Step 4
network address wildcard-mask area area-id
Define an interface on which OSPF runs and the area ID for that
interface. You can use the wildcard-mask to use a single
command to define one or more multiple interfaces to be
associated with a specific OSPF area. The area ID can be a
decimal value or an IP address.
Step 5
end
Return to privileged EXEC mode.
Step 6
show ip protocols
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.
