Setup Guide

NOTE: If using features like MD5 Authentication, ensure all the neighboring routers are also congured for MD5.
In the example below, an IP address is assigned to an interface and an OSPFv2 area is dened that includes the IP address of a Layer 3
interface.
The rst 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
Dell EMC Networking recommends using the interface IP addresses for the OSPFv2 router ID for easier management and troubleshooting.
To view the conguration, use the show config command in CONFIGURATION ROUTER OSPF mode.
OSPF, by default, sends hello packets out to all physical interfaces assigned an IP address that is a subset of a network on which OSPF is
enabled.
To view currently active interfaces and the areas assigned to them, use the show ip ospf interface command.
Example of Viewing Active Interfaces and Assigned Areas
Loopback interfaces also help the OSPF process. OSPF picks the highest interface address as the router-id and a Loopback interface
address has a higher precedence than other interface addresses.
Example of Viewing OSPF Status on a Loopback Interface
Conguring Stub Areas
OSPF supports dierent types of LSAs to help reduce the amount of router processing within the areas.
Type 5 LSAs are not ooded into stub areas; the ABR advertises a default route into the stub area to which it is attached. Stub area routers
use the default route to reach external destinations.
To ensure connectivity in your OSPFv2 network, never congure the backbone area as a stub area.
To congure a stub area, use the following commands.
1 Review all areas after they were congured to determine which areas are NOT receiving type 5 LSAs.
EXEC Privilege mode
show ip ospf process-id [vrf] database database-summary
2 Enter CONFIGURATION mode.
EXEC Privilege mode
configure
3 Enter ROUTER OSPF mode.
CONFIGURATION mode
router ospf process-id [vrf]
Process ID is the ID assigned when conguring OSPFv2 globally.
4 Congure the area as a stub area.
CONFIG-ROUTER-OSPF-id mode
area area-id stub [no-summary]
Use the keywords no-summary to prevent transmission into the area of summary ASBR LSAs.
Open Shortest Path First (OSPFv2 and OSPFv3)
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