IP R
OUTING
C
OMMANDS
-147
Command Usage
• OSPF is used to specify how routers exchange routing table
information.
• This command is also used to enter router configuration mode.
Example
Related Commands
network area (3-155)

router-id

Use this command to assign a unique router ID for this device within the
autonomous system. Use the no form to use the default router
identification method (i.e., the lowest interface address).
Syntax
router-id ip-address
no router-id
ip-address - Router ID formatted as an IP address.
Command Mode
Router Configuration
Default Setting
Lowest interface address
Command Usage
• The router ID must be unique for every router in the autonomous
system. Using the default setting based on the lowest interface address
ensures that each router ID is unique. Also, note that you cannot set
the router ID to 0.0.0.0 or 255.255.255.255.
• If this router already has registered neighbors, t he new router ID will
be used when the router is rebooted, or manually restarted by entering
the no router ospf followed by the router ospf command.
Console(config)#router ospf
Console(config-router)#