Concept Guide

show ip ospf process-id
DellEMC#show ip ospf 55555
Routing Process ospf 55555 with ID 10.10.10.10
Supports only single TOS (TOS0) routes
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Number of area in this router is 0, normal 0 stub 0 nssa 0
DellEMC#
Assigning an OSPFv2 Area
After you enable OSPFv2, assign the interface to an OSPF area. Set up OSPF areas and enable OSPFv2 on an interface with
the network command.
You must have at least one AS area: Area 0. This is the backbone area. If your OSPF network contains more than one area,
configure a backbone area (Area ID 0.0.0.0). Any area besides Area 0 can have any number ID assigned to it.
The OSPFv2 process evaluates the network commands in the order they are configured. Assign the network address that is
most explicit first to include all subnets of that address. For example, if you assign the network address 10.0.0.0 /8, you cannot
assign the network address 10.1.0.0 /16 because it is already included in the first network address.
When configuring the network command, configure a network address and mask that is a superset of the IP subnet configured
on the Layer-3 interface for OSPFv2 to use.
You can assign the area in the following step by a number or with an IP interface address.
● Enable OSPFv2 on an interface and assign a network address range to a specific OSPF area.
CONFIG-ROUTER-OSPF-id mode
network ip-address mask area area-id
The IP Address Format is A.B.C.D/M.
The area ID range is from 0 to 65535 or A.B.C.D/M.
Enable OSPFv2 on Interfaces
Enable and configure OSPFv2 on each interface (configure for Layer 3 protocol), and not shutdown.
You can also assign OSPFv2 to a Loopback interface as a virtual interface.
OSPF functions and features, such as MD5 Authentication, Grace Period, Authentication Wait Time, are assigned on a per
interface basis.
NOTE: If using features like MD5 Authentication, ensure all the neighboring routers are also configured for MD5.
In the example below, an IP address is assigned to an interface and an OSPFv2 area is defined that includes the IP address of a
Layer 3 interface.
The first bold lines assign an IP address to a Layer 3 interface, and theno shutdown command ensures that the interface is
UP.
The second bold line assigns the IP address of an interface to an area.
Example of Enabling OSPFv2 and Assigning an Area to an Interface
DellEMC#(conf)#int te 4/14
Dell(conf-if-te-4/14)#ip address 10.10.10.10/24
DellEMC(conf-if-te-4/14)#no shutdown
DellEMC(conf-if-te-4/14)#ex
DellEMC(conf)#router ospf 1
DellEMC(conf-router_ospf-1)#network 1.2.3.4/24 area 0
DellEMC(conf-router_ospf-1)#network 10.10.10.10/24 area 1
DellEMC(conf-router_ospf-1)#network 20.20.20.20/24 area 2
DellEMC(conf-router_ospf-1)#
DellEMC#
Dell EMC Networking recommends using the interface IP addresses for the OSPFv2 router ID for easier management and
troubleshooting.
Open Shortest Path First (OSPFv2 and OSPFv3)
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