User Manual UMN:CLIV5812G41710.2.6 OSPF AreaRouter configuration on OSPF network includes Area configuration with each interface,network. Area has various and special features. It needs to be configured pertinently tomake effective management on whole of OSPF network.OSPF network defines several router types to manage the Area. ABR (Area BorderRouter) is one of the router types to transmit information between Areas.ASBR (Autonomous System Border Router) is using OSPF on oneside and using otherrouting protocol except for OSPF on other interface or Area. ASBR exchanges areainformation between different routing protocols.Area types are various. The most principle Area types are Stub Area and NSSA (Not SoStubby Area).10.2.6.1 Area AuthenticationOSPF routers in specific Area can configure authentication for security of routinginformation. Encoding uses password based on text or MD5. To set password on interfaceassigned Area, use the ip ospf authentication-key and ip ospf message-digest-keycommands in interface mode, see Section 10.2.4.1 for more information.To configure authentication information for encoding, use the following command.Command Mode Descriptionarea {<0-4294967295> | A.B.C.D}authentication RouterConfigures authentication information which is basedon text encoding in the Area.area {<0-4294967295> | A.B.C.D}authentication message-digestConfigures authentication information which is basedon MD5 encoding in the Area.To delete configured authentication information for encoding, use the following command.Command Mode Descriptionno area {<0-4294967295> |A.B.C.D} authentication Router Deletes configured authentication information.10.2.6.2 Default Cost of AreaThe default cost of Area is configured only in ABR. ABR function is for delivering thesummary default route to stub area or NSSA, in that cases the default cost of area mustbe required. However, ABR which does not have stub area or NSSA can not use thefollowing command.To configure a default cost of Area, use the following command.Command Mode Descriptionarea {<0-4294967295> | A.B.C.D}default-cost <1-16777215> Router Configures a default cost of Area.
