NFD FIB Management Protocol¶

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

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

Command format¶

Request¶

Request is a Signed Command Interest with the following name:

/localhost/nfd/fib/<command-verb>/<command-options>/............................

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

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.
Note that Name field is required for 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 NFD Control Command specification.

Content of ControlResponse on success:

Field in ControlResponse block	Value
StatusCode	200
StatusText	"Success"
<StatusBody>	FibManagementOptions block, either echoed or with updated FaceId field

Content of ControlResponse on error:

Field in ControlResponse block	Value
StatusCode	4xx, 5xx, or other error codes based on RFC2616
StatusText	Human-readable description of the error
<StatusBody>	Not present

Operations¶

FIB management protocol supports five operations:

• insert: insert a FIB entry
• delete: delete a FIB entry
• add-nexthop: add a nexthop to a FIB entry
• remove-nexthop: remove a nexthop from a FIB entry
• set-strategy: set the forwarding strategy for a namespace

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

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

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¶

command-verb: set-strategy

This command sets the forwarding strategy for a namespace.

Required fields in FibManagementOptions block:

• Name
• Strategy

Strategy must be a Name that represents a builtin strategy:

• ndn:/localhost/nfd/strategy/best-route
• ndn:/localhost/nfd/strategy/broadcast
• ndn:/localhost/nfd/strategy/ncc

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

If the Strategy does not exist, the response has StatusCode 405.

TLV-TYPE assignments¶

Type	Assigned value	Assigned value (hex)
FibManagementOptions	104	0x68
FaceId	105	0x69
Cost	106	0x6a
Strategy	107	0x6b