F Commands

This chapter describes the Cisco NX-OS Open Shortest Path First (OSPF) commands that begin with F.

feature ospf

To enable the Open Shortest Path First Protocol (OSPF), use the feature ospf command. To disable OSPF, use the no form of this command.

feature ospf

no feature ospf

Syntax Description

This command has no arguments or keywords.

Command Default

Disabled

Command Modes

Command HistoryGlobal configuration mode

Release
Modified

5.0(3)N1(1)

This command was introduced.


Usage Guidelines

You must enable the OSPF feature before you can configure OSPF.

Note In Cisco NX-OS Release 5.0(3)N1(1), a software upgrade on the Cisco Nexus 5548 switch and the Cisco Nexus 5596 switch that has the Layer 3 features enabled is disruptive. You must reload the switch and the Cisco Nexus 2000 Series Fabric Extender.

This command requires the LAN Base Services license.

Examples

This example shows how to enable the OSPF feature: 

switch# configure terminal

switch(config)# feature ospf

switch(config)#

 
   
 
    
   
 This example shows how to disable the OSPF feature: 
 
    
   
 
    
switch# configure terminal

 
   
 
    
   
 
    
switch(config)# no feature ospf

 
   
 
    
   
 
    
switch(config)#

 
   
 
    
   
 Related Commands
 
   
 
    
 
      
      
      
 
        
        

          Command 
        
 		 
        
        

          Description 
        
 		 
      
 
      
 
       
 router ospf 
 		 
       
 Creates an OSPF instance. 
 		 
      
 
      
 
       
 show feature 
 		 
       
 Displays the status of features on a switch. 
 		 
      
 
      
 
       
 show ospf 
 		 
       
 Displays OSPF configuration information. 
 		 
      
 
      
    
 
   
 
   
 
   
 
 
     
    
    
   
 flush-routes (OSPF) 
 
    
   
 To flush routes on a restart for the Open Shortest Path First (OSPF) protocol, use the flush-routes command. To disable this feature, use the no form of this command. 
 
    
   
flush-routes 
 
    
   
no flush-routes 
 
    
   
 Syntax Description 
 
    
   
 This command has no arguments or keywords. 
 
    
   
 Command Default 
 
    
   
 Disabled 
 
    
   
 Command Modes 
 
    
   
 Command HistoryRouter configuration mode
 
   
 
    
 
      
      
      
 
        
        

          Release 
        
 		 
        
        

          Modification 
        
 		 
      
 
      
 
       
 5.0(3)N1(1) 
 		 
       
 This command was introduced. 
 		 
      
 
      
    
 
   
 
   
 
   
 
 
    
   
 Usage Guidelines 
 
    
   
 This command causes OSPF to unregister from the unicast RIB when OSPF shuts down. The unicast RIB removes all the routes associated with this OSPF instance. If you do not configure the flush-routes command, OSPF does not unregister and the OSPF routes will be stale. The OSPF routes are eventually removed from the unicast RIB after a timeout period. 
 
    
   
 This command requires the LAN Base Services license. 
 
    
   
 Examples 
 
    
   
 This example shows how to flush routes for an OSPF restart: 
 
    
   
 
    
switch# configure terminal

 
   
 
    
   
 
    
switch(config)# router ospf 202

 
   
 
    
   
 
    
switch(config-router)# flush-routes

 
   
 
    
   
 
    
switch(config-router)#

 
   
 
    
   
 Related Commands
 
   
 
    
 
      
      
      
 
        
        
 
         Command 
        
 		 
        
        
 
         Description 
        
 		 
      
 
      
 
       
 show ip ospf 
 		 
       
 Displays OSPF information.