A number of steps are required when enabling OSPFv2 on a device. 
 
 
 
 Before you begin
 
    Consider the following when enabling OSPFv2 on a device. 
    
 
     
      -  Redistribution must be enabled on devices configured to operate as ASBRs. 
      
  
      -  All device ports must be assigned to one of the defined areas on an OSPF device. When a port is assigned to an area, all corresponding subnets on that port are automatically included in the assignment. 
      
  
    
 
   
 Procedure
-  
       Enter the 
         router ospf command in global configuration mode to enable OSPF on the device. 
       
    
 -  
       Assign the areas to which the device will be attached. 
       
    
 -  
       Assign individual interfaces to the OSPF areas. 
       
    
 -  
       Assign a virtual link to any ABR that does not have a direct link to the OSPF backbone area. 
       
    
 -  
       Refer to 
          Changing default settings.