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FibMgmt » History » Revision 15

Revision 13 (Junxiao Shi, 01/30/2014 12:53 PM) → Revision 15/44 (Alex Afanasyev, 01/30/2014 04:16 PM)

# NFD FIB Management Protocol 

 The **FIB management protocol** allows an entity to manipulate the FIB entry. 

 The FIB management protocol uses [[Signed Interests]]-Data exchange. 
 The command request and response follows the [[ControlCommand|NFD Control Command specification]] 

 ## Command format 

 ### Request 

 Request is a signed Interest with the following name: 

     /localhost/nfd/fib/<command-verb>/<command-options>/<timestamp>/<SignatureInfo>/<SignatureValue> 

     \                  / \                                / \                                            / 
      -------    -------     -------------    ---------------     --------------------    -------------------- 
             \/                         \/                                        \/ 
     NFD Control Command         FibManager command               Signed Interest related information 
     to FibManager               and command options 


 Command options is defined as a TLV-encoded ``FibManagementOptions`` block. 
 Each individual command defines a subset of required and optional elements in the ``FibManagementOptions`` block. 

     FibManagementOptions ::= FIB-MANAGEMENT-OPTIONS-TYPE TLV-LENGTH 
                                Name? 
                                FaceId? 
                                Cost? 
                                Strategy? 
    
     // Name defined in NDN-TLV spec 

     FaceId                 ::= FACEID-TYPE TLV-LENGTH 
                                nonNegativeInteger 
    
     Cost                   ::= COST-TYPE TLV-LENGTH 
                                nonNegativeInteger 

     Strategy               ::= STRATEGY-TYPE TLV-LENGTH 
                                Name 

 ### Response 

 Command response is a Data packet that contains TLV-encoded ``ControlResponse`` block, defined in [[ControlCommand|NFD Control Command specification]]. 

 The response has StatusCode 200 if the command succeeds. 

 <!-- Alex: Should positive responses contain TLV-Encoded ``FibManagementOptions`` block related to the command (after StatusText)? --> 

 Any other status code (4xx, 5xx, [?]) mean error. 
 Description of the error can be present in ``StatusText`` field of ``ControlResponse`` command. 

 ### Operations 

 **FIB management protocol** protocol supports five operations: 

 * insert a FIB entry (command-verb: ``insert``) 
 * delete a FIB entry (command-verb: ``delete``) 
 * add a nexthop to a FIB entry (command-verb: ``add-nexthop``) 
 * remove a nexthop from a FIB entry (command-verb: ``remove-nexthop``) 
 * set the forwarding strategy for a namespace (command-verb: ``set-strategy``) 

 ## Insert a FIB entry 

 **command-verb:** ``insert`` 

 Required fields in ``FibManagementOptions`` block: 

 * ``Name`` 

 If a FIB entry for Name already exists, this command does nothing, but is still considered successful. 

 ## Delete a FIB entry 

 **command-verb:** ``delete`` 

 Required fields in ``FibManagementOptions`` block: 

 * ``Name`` 

 If a FIB entry for Name does not exist, this command does nothing, but is still considered successful. 

 ## Add a nexthop 

 **command-verb:** ``add-nexthop`` 

 This command adds a nexthop to an existing FIB entry. 

 Required fields in ``FibManagementOptions`` block: 

 * ``Name`` 
 * ``FaceId`` 
 * ``Cost`` 

 If a nexthop of same ``FaceId`` exists on the FIB entry, its cost is updated. 

 **FaceId** is the FaceId returned in [[FaceMgmt|NFD Face Management protocol]]. 

 If **FaceId** is set to zero, it is implied as the face of the entity sending this command. 

 If the FIB entry does not exist, the response has StatusCode 404. 

 ## Remove a nexthop 

 **command-verb**: ``remove-nexthop`` 

 This command removes a nexthop from a FIB entry. 
 Removing the last nexthop in a FIB entry will not automatically delete the FIB entry. 

 Required fields in ``FibManagementOptions`` block: 

 * ``Name`` 
 * ``FaceId`` 

 **FaceId** is the FaceId returned in *NFD Face Management protocol*. 
 If **FaceId** is set to zero, it is implied as the face of the entity sending this command. 


 If the FIB entry does not exist, the response has StatusCode 404. 

 If the specified nexthop does not exist on the FIB entry, this command does nothing, 
 but is still considered successful. 


 ## Set strategy 

 This command sets a forwarding strategy for a namespace. 

 The format of this command will be defined in a later version of this spec. 

 Required fields in ``FibManagementOptions`` block: 

 * ``Name`` 
 * ``Strategy`` 

 ## TLV-TYPE assignments 

 Type                                          | Assigned value      | Assigned value (hex) 
 ------------------------------------------- | ----------------- | -------------------- 
 FibManagementOptions                          | 104 129                 | 0x68 0x81 
 FaceId                                        | 105 130                 | 0x69 0x82 
 Cost                                          | 106 131                 | 0x70 0x83 
 Strategy                                      | 107 132                 | 0x7a 0x84