31.7 Commands at a glance

Following is a list of unicast routing related commands used in simulation scripts:

$ns_ rtproto routing-proto args

where <routing-proto> defines the type of routing protocol to be used, like Static, Manual, Session , DV etc. args may define the list of nodes on which the protocol is to be run. The node list defaults to all nodes in the topology.

Internal methods:

$ns_ compute-routes

This command computes next_hop information for all nodes in the topology using the topology connectivity. This next_hop info is then used to populate the node classifiers or the routing tables. compute-routes calls compute-flat-routes or compute-hier-routes depending on the type of addressing being used for the simulation.

$ns_ get-routelogic

This returns a handle to the RouteLogic object (the routing table), if one has been created. Otherwise a new routing table object is created.

$ns_ dump-routelogic-nh

This dumps next hop information in the routing table.

$ns_ dump-routelogic-distance

This dumps the distance information in the routing table.

$node add-route dst Target

This is a method used to add routing entries (nexthop information) in the node's routing table. The nexthop to <dst> from this node is the <target> object and this info is added to the node's classifier.

$routelogic lookup srcid destid

Returns the id of the node that is the next hop from the node with id srcid to the node with id destid.

$routelogic dump nodeid

Dump the routing tables of all nodes whose id is less than nodeid. Node ids are typically assigned to nodes in ascending fashion starting from 0 by their order of creation.

rtobject dump-routes fileID

Dump the routing table to the output channel specified by fileID. fileID must be a file handle returned by the Tcl open command and it must have been opened for writing.

$rtobject rtProto? proto

Returns a handle to the routing protocol agent specified by proto if it exists at that node. Returns an empty string otherwise.

$rtobject nextHop? destID

Returns the id of the node that is the next hop to the destination specified by the node id, <destID>.

$rtobject rtpref? destID

Returns the preference for the route to destination node given by destid.

$rtobject metric? destID

Returns metric for the route to destid.