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NAME

imcrc - IMC scheme configuration commands file

DESCRIPTION

IMC scheme configuration commands are passed to imcadmin either in a file of text lines or interactively at imcadmin's command prompt (:). Commands are interpreted line-by line, with exactly one command per line.

IMC scheme configuration commands simply establish which nodes are the local node's parents and children within a single IMC multicast tree. This single spanning tree, an overlay on a single BP-based network, is used to convey all multicast group membership assertions and cancellations in the network, for all groups. Each node privately tracks which of its immediate "relatives" in the tree are members of which multicast groups and on this basis selectively forwards -- directly, to all (and only) interested relatives -- the bundles destined for the members of each group.

Note that all of a node's immediate relatives in the multicast tree must be among its immediate neighbors in the underlying network. This is because multicast bundles can only be correctly forwarded within the tree if each forwarding node knows the identity of the relative that passed the bundle to it, so that the bundle is not passed back to that relative creating a routing loop. The identity of that prior forwarding node can only be known if the forwarding node was a neighbor, because no prior forwarding node (aside from the source) other than the immediate proximate (neighboring) sender of a received bundle is ever known.

IMC group IDs are unsigned integers, just as IPN node IDs are unsigned integers. The members of a group are nodes identified by node number, and the multicast tree parent and children of a node are neighboring nodes identified by node number.

The formats and effects of the IMC scheme configuration commands are described below.

GENERAL COMMANDS

  • ?

    The help command. This will display a listing of the commands and their formats. It is the same as the h command.

  • #

    Comment line. Lines beginning with # are not interpreted.

  • e { 1 | 0 }

    Echo control. Setting echo to 1 causes all output printed by ipnadmin to be logged as well as sent to stdout. Setting echo to 0 disables this behavior.

  • h

    The help command. This will display a listing of the commands and their formats. It is the same as the ? command.

KINSHIP COMMANDS

  • a node_nbr { 1 | 0 }

    The add kin command. This command adds the neighboring node identified by node_nbr as an immediate relative of the local node. The Boolean value that follows the node number indicates whether or not this node is the local node's parent within the tree.

  • c node_nbr { 1 | 0 }

    The change kin command. This command changes the parentage status of the indicated relative according to Boolean value that follows the node number, as noted for the add kin command.

  • d node_nbr

    The delete kin command. This command deletes the immediate multicast tree relative identified by node_nbr. That node still exists but it is no longer a parent or child of the local node.

  • i node_nbr

    This command will print information (the parentage switch) for the multicast tree relative identified by node_nbr.

  • l

    This command lists all of the local node's multicast tree relatives, indicating which one is its parent in the tree.

EXAMPLES

  • a 983 1

    Declares that 983 is the local node's parent in the network's multicast tree.

SEE ALSO

imcadmin(1)